JPH08213123A - Cmc adapter - Google Patents

Abstract

PURPOSE: To freely and quickly interpose and insert a CMC for connection to a signal transmitting passage even in the future without providing a space for mounting the CMC on a printed wiring board unit of the device side in a CMC adapter with a built-in CMC(common mode choke coil). CONSTITUTION: A first connector 42, which can be connected to a connector for connecting a printed wiring board unit and a cable connector, and a second connector 43, which can be connected to the cable connector, are provided in both ends. A CMC 69 is provided in the printed wiring board 61 for connecting the first connector 42 to the second connector 43, and terminals of the first connector 43 and the second connector 43 are connected to each other through the CMC 69.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CMC adapter having a CMC (common mode choke coil) built therein.

For example, in a digital exchange,
When it is necessary to prevent the generation of harmful electromagnetic waves that are inductively emitted from the cable for connecting devices when performing data transmission using the balanced transmission method using balanced transmission elements between devices, the circuit on the driver output side of the balanced transmission elements It is effective to interpose CMC in the.

FIG. 10 is a side view showing the main part of the apparatus. In the figure, connectors 2 and 3 are provided on both front and rear surfaces of a backboard 1 which is a printed wiring board of a shelves (neither of which is shown) mounted in a device rack. This connector has connectors 2 and 3 formed by attaching frame-shaped connector housings 5 and 6 to a large number of connector pins 4 that are fixed to the back board 1 by penetration and project on both sides. The connector pin 4 is for these connector housings 5,
6 are aligned and projected at predetermined intervals.

The connector housing 5 on the front side is mounted in close contact with the backboard 1, and the connector housing 6 on the rear side is mounted on the notches of the metal fittings 7 and 8 which are also mounted to reinforce the backboard 1 at both ends. It is attached by inserting the hook 9 of. Therefore, the connector housing 6 is spaced from the backboard 1 by the height of the metal fittings 7, 8.

A connector 2 on the front side of the backboard 1 has a printed circuit board unit 1 in which a predetermined circuit is formed.
1 is inserted along the guide from the opening of the front surface of the device not shown, and is connected by a printed wiring board connector 12 so that it can be plugged in and unplugged. The printed wiring board connector 12 is a socket type so that the connector pins 4 of the connector 2 can be received and connected.

The printed wiring board unit 11 is equipped with a balanced transmission element 14, which is indicated by a symbol, and is mounted on the printed wiring board. The pair wiring pattern 15 of the printed wiring board, the printed wiring board connector 12, and the front-side connector are provided. It is connected and led out to the connector pin 4 of the connector 3 on the back side via 2. The balanced transmission element 14 is typically shown only for one location.

A cable connector 17 is inserted and connected to the connector 3 on the back side. The cable connector 17 is likewise socket-type so that it can receive and connect the connector pins 4 of the connector 3 on the rear side.

A cable 18 connected to a circuit portion of another device is led out from the back side of the cable connector 17, and a serrated locking projection 21 and a tip end are bifurcated on the side surface of the ridge 19. A slide piece 22 for releasing the lock, the rear side of which protrudes, is provided so as to be slidable in the front-rear direction.

The connector housing 6 constituting the rear connector 3 will be described with reference to FIG. 11. FIG. 11A is a front view, FIG. 11B is a longitudinal side view, and FIG.
Is a side view in the width direction.

The connector housing 6 is made of a synthetic resin molding and has two connector portions 25, 25 into which the cable connector 17 can be inserted and connected. At both ends, hooks 9 are attached to the tips of two protrusions 26 that are elastically deformable in the width direction.
Are formed.

Inside the bottom surface of the connector portion 25, connector pin insertion holes 27 for receiving the connector pins 4 implanted in the backboard 1 are arranged in two rows at predetermined intervals, for example, 2.5 m.
It is provided at m intervals.

A groove 28 for receiving the ridge 19 formed on the side surface of the cable connector 17 on one side surface, and an engaging piece 3 made of an elastic piece by notches 29 on both sides of the groove 28.
1 is formed. The locking piece 31 is provided with a cutout hole 32 extending from the bottom surface side. Therefore, the locking piece 31 has a thin plate shape, and the tip portion thereof can be easily elastically deformed in the width direction of the connector housing 6.

The cable connector 1 is attached to the connector 3 on the rear side.
When 7 is inserted, when the slope of the saw-toothed locking projection 21 formed in the projection 19 which is inserted into the groove 28 elastically deforms the locking piece 31 and passes over it, the locking projection 21 engages. It fits into the notch hole 32 of the stop piece 31, and the locking projection 21
The cable connector 17 is locked by the upright surface so that it does not come out.

When the cable connector 17 is detached, when the slide piece 22 for releasing the lock is pushed in, the forked portion of the tip enters the inner surface of the lock piece 31 from both sides of the lock protrusion 21 and its sloped surface. Since the locking piece 31 is elastically deformed and the locked state by the push-up locking projection 19 is released, the cable connector 17 can be pulled out in this state.

FIG. 12 shows a symbol of a typical example of CMC in FIG. 12A and a plan view in FIG. 12B. CMC35
Is a ring-shaped molding core 36 made of ferrite, for example.
In addition, the pair of pair wires 37 are wound a predetermined number of times and function to prevent passage of a necessary harmful signal component. Depending on the purpose, a plurality of pairs of wires may be wound.

[0016]

2. Description of the Related Art Conventionally, as shown in FIG. 10, a cable connector 17 is used when data is transmitted via a balanced transmission element 15 mounted on a printed wiring board unit 11 on the device side in a digital exchange, for example.
In the case where a harmful electromagnetic wave is stimulated to be emitted from the cable 18 of FIG.
The intervening connection of the CMC 35 as shown in FIG.

[0017]

Since all of the above are carried out for many balanced transmission elements 14, the printed wiring board unit 1 on which the CMC 35 is mounted is mounted.
It was either a replacement with 1 or a remodeling work was carried out locally, and it took a lot of time and effort. It is costly to implement the device in advance, and even if it is possible to implement the device, it is a problem that the device must be stopped for a long time for the work at a later date.

In any case, it is necessary to secure a mounting space on the surface of the printed wiring board unit 11,
Therefore, the mounting area for the circuit configuration is reduced, which is an obstacle to high-density mounting.

In view of the above-mentioned conventional problems, the present invention does not require a mounting space for the printed wiring board unit 11 on the side of the apparatus, and the CMC is added to the transmission line even at a later date. It is an object of the present invention to provide a CMC adapter which can be easily and promptly performed by arbitrarily inserting it.

[0020]

According to the gist of the constitution of the present invention for solving the above problems, according to the first means, it is possible to connect to a connector for connecting a printed wiring board unit and a cable connector. A first connector and a second connector that can be connected to the cable connector are provided at both ends, and a CMC is provided on a printed wiring board that connects the first connector and the second connector. It is a CMC adapter in which the terminals of the first connector and the terminals of the second connector are connected.

According to the second means, in addition to the first means,
The first connector side is provided with a locking projection capable of engaging with the locking piece of the connector and a slide piece for unlocking, and the second connector side is provided with a locking projection of the cable connector. C provided with engaging pieces that can be engaged
It is an MC adapter.

According to the third means, in addition to the first means,
The printed wiring board is a CMC adapter including a ground pattern for connecting the shield braid of the cable to a ground circuit on the side of the device on which the printed wiring board unit is mounted.

[0023]

According to the above-mentioned structure of the present invention, the first connector of the CMC adapter is inserted and connected to the connector for connecting the printed wiring board unit on the device side and the cable connector, and the cable is connected to the second connector of the CMC adapter. By inserting and connecting the connector, the circuit of the printed wiring board unit and the transmission line of the cable are connected via the CMC mounted on the printed wiring board in the CMC adapter.

In this way, a countermeasure can be taken immediately by removing the cable connector connected to the device side connector and inserting and connecting the CMC adapter between them. The first connector side of the CMC adapter is provided with the locking projection for the locking piece of the device side connector and the slide piece for unlocking, so that the CMC adapter can be reliably pulled out from the device side connector. It is possible to lock and lock it and to remove it easily. Further, since the second connector side is provided with the locking piece for receiving and locking the locking projection of the cable connector, the retaining locking state can be similarly achieved.

Further, since the printed wiring board in the CMC adapter includes a ground pattern for connecting the shield braid covering the periphery of the transmission line of the cable to the ground circuit on the device side, more effective leakage prevention is provided. The effect is obtained.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The CMC adapter of the present invention will be described in detail below with reference to the drawings by way of specific embodiments. Note that the same reference numerals are given to the same parts throughout the drawings.

FIG. 1 shows an embodiment of the CMC adapter of the present invention and an example of application to a device, together with a side view of the essential parts of the device. The main part of the apparatus and the cable connector 17 shown in FIG. 1 are the same as those in FIG. In addition, the connector housing 6 of the backside connector 3 of the backboard 1 is also shown in FIG.
1 is the same as that shown in FIG. Therefore, the same reference numerals are given to these portions and the description of the configuration will be omitted. Therefore, if necessary, refer to the already explained portions of FIGS. 10 and 11 together with the reference numerals.

Referring to FIG. 1, the CMC adapter 4 of the present invention is shown.
1 is arranged between the back side connector 3 of the backboard 1 and the cable connector 17. CMC adapter 41
The configuration of the first connector 42 that can be connected to the connector 3 of the backboard 1 on the device side to which the printed wiring board unit 11 is connected, and the first connector 42 that can be connected to the cable connector 17 that can be directly connected to the connector 3 Two connectors 43 are provided at both ends.

According to another configuration, the CMC adapter 41
Is the CMC adapter body 45 and the CMC adapter case 4
6, and both ends of the CMC adapter body 45 and both ends of the CMC adapter case 46 that surrounds the CMC adapter body 45 form a first connector 42 and a second connector 43.

A locking protrusion 47 capable of engaging with the locking piece 31 of the connector 3 and a sliding piece 48 for unlocking are provided on the front surface of the CMC adapter case 46, and the second connector 43 side. The locking projection 21 of the cable connector 17
A locking piece 49 that can be engaged with is provided.

The portions indicated by reference numeral 51 are four connecting screws for assembling and integrally connecting the CMC adapter 41. 2A and 2B show the CMC adapter body 45. FIG. 2A is a front view, FIG. 2B is a side view, and FIG. 2C is a view taken along the line AA in FIG. 2B.

The first connector block 53 which is molded by synthetic resin and constitutes the first connector 42, and the upper and lower two rows of socket type contact pieces for receiving and connecting the connector pins 4 of the connector 3 thereinto the rear side. A soldering terminal 54 extending in the direction of the second connector, and a second connector block 55 forming the second connector 43 and molded by synthetic resin molding.
Inside thereof, soldering terminals 57 extending inward from the upper and lower two rows of connector pins 56 connected to the socket type terminals of the cable connector 17, the first connector 42 and the second connector 42 on both sides.
Printed wiring board 61 for connecting and connecting to the connector 43 of
And consisting of

On the left and right sides of the first connector block 53, there are stepped portions 63 which are recesses and upper and lower protrusions 64 extending in the width direction. The second connector block 55 is composed of a wall surface in three directions and notches 66 formed on both sides of a groove 65 for receiving the ridge 19 of the cable connector 17, and an elastic locking piece 49 is formed on the wall surface. To be done. The locking piece 49 is provided with a notch hole 67 extending from the bottom portion in the front end direction, and the locking projection 21 of the cable connector 17 is engaged with the cutout hole 67 so that the locking piece is locked.

On one end side of the printed wiring board 61, a soldering pattern is formed on the upper and lower surfaces for soldering and connecting the soldering terminals 54 on the first connector side. There is.

On the other end side of the printed wiring board 61, soldering patterns are formed on the upper and lower surfaces for soldering connection of the soldering terminals 57 on the second connector side, and both sides are connected by soldering. ing.

Four CMCs 69 are mounted and mounted in the center of the printed wiring board 61 in the width direction, and lead patterns 71 extending from the respective soldering lead terminals to both sides.
Are connected to the soldering terminals 54 and 57 of the first and second connectors 42 and 43. Two rows of terminals 54, 5
7 are connected to the terminals on the rear surface side of the printed wiring board 61 through the via holes 72, respectively, by the lead pattern 71 on the rear surface.

The component indicated by reference numeral 73 is soldered and connected by the soldering terminals on both sides, and the lead pattern 71
A ferrite element, such as a ferrite bead, connected to the first and second connector terminals 54 and 57.

The cutout holes 74 formed at the four corners of the printed wiring board 61 are parts for inserting and assembling the screws 51. The CMC 69 is basically as shown in FIG. 12, and according to the CMC 69, it is housed in a package and lead terminals for 6 pieces are led out on both sides. That is, it is a pair of wire pairs of three to plural. Therefore, the connector terminals 54 and 57 are a set of the front surface and the back surface of the printed wiring board 61 to form a balanced transmission line.

3 and 4 show the CMC adapter case, particularly its case body 75. FIG. 3 (a) is a front view, FIG. 3 (b) is a side view, and FIG. 3 (c) is a drawing (a). B-
The side sectional view of arrow B is shown. In addition, FIG. 4A is a rear side view (inner side view), FIG. 4B is a view taken along the line C-C in FIG. 4A, and FIG. And a perspective view, respectively.

The case main body 75 is an integrally molded product made of a synthetic resin mold, and is composed of three wall surfaces. A ridge 76 protruding toward the first connector 42 is provided on the main wall surface.
And a bent guide groove 77 communicating with this ridge.
And projections 78 for holding and accommodating the stepped portion 63 of the first connector block 53 are formed on the opposite side surfaces on both sides. A notch 79 for avoiding the locking piece 49 is formed on the side that houses the second connector block 55.

Further, screw insertion holes 81 having counterbores for inserting the connecting screws 51 are formed at two positions on both sides. A serrated locking protrusion 47 and concave grooves 82 are formed on both sides of the upper surface of the protrusion 76.

Guide recesses 83 along both sides of the open surface of the guide groove 77 that covers the second connector block 55.
Are formed. A concave groove 84 for accommodating the protrusion 64 of the first connector block 53, the CMC 69 and the ferrite element 73 of the printed wiring board 61, and the concave portions are formed on the inner surface side so as to avoid the soldering terminals 54 and 57. A convex surface 85 that is in contact with the surface of the lead pattern 71 is formed.

FIG. 5 shows an external view of the slide piece 48 for unlocking. Figure (a) is a front view, Figure (b) is a side view, Figure (c) is a view taken along the arrow EE of Figure (b), Figure (d) is a view taken along the arrow FF of Figure (b), Is.

The unlocking slide piece 48 is a synthetic resin molded product, and is fitted in the bent guide groove 77 of the CMC adapter case 75, and is bent in a front view so that it can be moved a predetermined distance in the front-rear direction. Shaped body 8
8 has a bifurcated projection 89 on both sides of the locking projection 47, the tip of which is formed as an inclined surface 91, and the lower surface 92 thereof is formed in the groove 82 of the CMC adapter case 75. Fit together. Further, on the rear end side, protrusions 93 are formed on both side surfaces.

FIG. 6 shows an external view of the cover of the CMC adapter case. (A) is an inner surface side of a front view, (b) is a side view, (c) is a GG arrow view of (b),
Is. Since the cover 95 covers the open one surface of the three surfaces where the CMC adapter case 75 is formed, it is a plate-like member and is a synthetic resin molded product.

On the inner surface side, the recesses 97 and 98 that avoid the portions of the soldering terminals 54 and 57 of the CMC adapter body 45 and the groove 9 that fits into the ridge 64 of the first connector block 53 are provided.
9 is formed, and the portion of the flat surface 101 is a surface in contact with the back surface of the printed wiring board 61 of the CMC adapter body 45. Four holes 102 are CMC adapter case 75
This is a hole for inserting the screw 51 for integral connection in combination with the above, and a counterbore for sinking the screw head is provided on the front surface side.

The assembly sequence with the above configuration will be described below. First, referring to FIG. 7, as shown in FIG. 7A, the CMC adapter body 45 is fitted into the CMC adapter case 75 through the opening surface thereof. It can be clearly seen that the CMC adapter body 45 is accurately fitted in the CMC adapter case 75 without any gap. Such a fit is such that they do not move in either direction. At this time, as described below in advance, C
A slide piece 48 for unlocking is fitted in the guide groove 77 of the MC adapter case 75.

Then, as shown in FIG.
The cover 95 covers the opening of the C adapter case 75.
Then, the screws 51 are put through the four screw holes, and a nut is applied to the opposite surface to fasten them together to complete the assembly. In this figure (b), the back side of the CMC adapter 41 is shown.

Referring to FIG. 8 (a), the front side is shown, FIG. 8 (b) is a side view thereof, and further referring to FIG. 8 (c), H--H in FIG. 8 (b). A view from the arrow is shown.

When assembled as described above, the CM
Since the printed wiring board 61 of the C adapter body 45 is sandwiched between the convex surface 85 of the CMC adapter case and the flat surface 101 of the cover 95, the movement in the thickness direction is restricted, and it can no longer move in any direction as a whole. Disappear.

As shown in FIG. 8 (a), the fitting of the slide piece 48 for unlocking is performed by the CMC.
The protrusion 93 at the rear end of the slide piece is engaged with the opening guide recess 83 on the rear end side of the guide groove 77 of the adapter case 75 in an orthogonal posture, and then the slide piece 48 is tilted into the guide groove 77. It can be easily combined. When assembled, the protrusions 93 follow the guide recesses 83 as shown in FIG. 7C, so that the slide piece 48 does not fall out of the guide groove 77.

In the state of FIG. 8A, the slide piece 48 is in the retracted position with respect to the guide groove 77, and the guide groove 77
It is possible to move forward for a distance corresponding to the gap S with respect to the bent portion, and to move back and forth during that time.

The reason why the unlocking slide piece 48 is bent is that the cable connector 17 can be directly inserted and connected to the device side connector 3 as shown in FIG. Since the locking protrusion 21 and the locking piece 31 can be engaged in this state, the CMC adapter 41 interposed between them needs to lock both as shown in FIG. Therefore, the locking projection 47 is provided at the same position on the first connector 42 side, and the locking piece 4 is provided at the same position on the second connector 43 side.
This is because it is equipped with 9.

The ferrite element 73 mounted on the printed wiring board 61 in the CMC adapter body 45 is a CMC.
When the adapter 41 is connected to the cable connector 17,
It is adapted to be connected to the shield braid in the sheath of the cable 18 via the cable connector 17.

The shield braid covers the balanced transmission line and the like in the cable 18 to prevent noise components from the outside space from invading the inside thereof, and to shield the induced electromagnetic wave from the cable 18 from being emitted. It is a net assembly of conductive wires for.

The CMC adapter 41 is a connector 3 on the device side.
Is connected to a ground circuit on the device side, for example, a signal ground circuit or a ground ground circuit.

As described above, the CMC adapter 4
By the insertion intervening connection of 1, the shield braid in the cable and the ground circuit on the device side are ground-connected by the lead pattern 71 included in the CMC adapter 41. This ground connection can effectively suppress harmful signal components in this portion by interposing a ferrite element 73 such as a ferrite bead.

The connection between the CMC adapter 41 and the device side connector 3 will be described with reference to FIG. 9. As shown in FIG. 9A, the first connector 42 of the CMC adapter 41 faces the connector 3. Let In this case, the unlocking slide piece 48 is in the retracted position, but this is not essential. Then, the first connector 42 is inserted into the connector 3 as indicated by the arrow.

As shown in FIG. 6B, the locking piece of the connector housing 6 is inserted by the entry of the tip slope of the locking projection 47 on the ridge 76 which is inserted into the groove 28 as the connector 3 is inserted. 31 is bent and deformed to be deformed, and the locking projection 47
Allow the passage of. As shown in FIG. (C), when the locking protrusion 47 fits into the cutout hole 32 of the locking piece 31,
The locking piece 31 elastically returns to the restoring position, and the CMC adapter 41 is connected to the connector 3 and locked so that it does not come off. In this case, assuming that the slide piece 48 for unlocking is at the advanced position, the slope 91 of the tip of the projection 89 is pressed along with the restoration of the lock piece 31, thereby retracting the slide piece 48 for unlocking. It will be pushed to the position.

To remove the CMC adapter 41 from the connector 3, the slide piece 48 for releasing the lock is pushed forward with the fingers, and the projection 89 as shown in FIG.
The leading end of the locking piece 31 is pushed up along the inclined surface 91 at the leading end of the locking piece 31. By this, the locking projection 4
7 is that the engagement state with the end of the cutout hole 32 of the locking piece 31 is released, so that the state can be maintained and the CMC adapter 41 can be pulled out easily. Of course, it is preferable that the CMC adapter 41 and the cable connector 17 are removed before performing the procedure.

In the present invention, the CMC mounted in the CMC adapter can be applied to the required one balanced transmission line, if necessary. It is to be included in the track.

Further, the present invention is not limited to suppressing the emission of unnecessary electromagnetic waves from the inside of the device to the outside, but can also be applied to prevent the adverse effect on the circuit inside the device from the outside. is there.

Also for the first and second connectors, the combination of plug type, socket type and the like can be arbitrarily selected according to the situation.

[0064]

As described above in detail, the CM of the present invention
According to the C adaptor, the CMC mounting space is not required in the printed wiring board unit on the device side, and the CMC can be additionally inserted in the transmission line as required at a later date, easily and immediately. Is something that can be done.

Furthermore, since the cross-sectional shape is substantially the same as that of the cable connector and is compact, it can be applied to existing existing devices without any problem without affecting adjacent connectors.

Since the device-side connector and the cable connector are also provided with locking means for retaining in the same manner, the locking can be released in the same manner as the conventional one without accidental disengagement. Operability is good because it can be performed.

As described above, the practical effect when applied to various devices is extremely remarkable.

[Brief description of drawings]

FIG. 1 is an example of a CMC adapter of the present invention and an example of application to a device.

FIG. 2 One embodiment of the CMC adapter body of the present invention

FIG. 3 is a CMC adapter case of the present invention (No. 1).

FIG. 4 is a CMC adapter case of the present invention (No. 2).

FIG. 5: Slide piece for unlocking

FIG. 6 is a cover of the CMC adapter case of the present invention.

FIG. 7 is an assembly diagram (1) of the CMC adapter of the present invention.

FIG. 8 is an assembly diagram of the CMC adapter of the present invention (No. 2)

FIG. 9 is an explanatory view of the connection between the CMC adapter and the connector.

FIG. 10 is a side view of an essential part of the device according to the present invention.

FIG. 11 is a connector housing according to the present invention.

FIG. 12 shows an example of CMC according to the present invention.

[Explanation of symbols]

 1 Backboard 2,3 Connector 4 Connector Pin 5,6 Connector Housing 7,8 Metal Fitting 9 Hook 11 Printed Wiring Board Unit 12 Printed Wiring Board Connector 14 Balanced Transmission Element 15 Pair Wiring Pattern 17 Cable Connector 18 Cable 19 Protrus 21 Locking Protrusion 22 Sliding piece for unlocking 25 Connector portion 26 Protrusion 27 Connector pin insertion hole 28 Groove 29 Notch 31 Locking piece 32 Notch hole 35 CMC 36 Molded core 37 Pair wire 41 CMC adapter 42 First connector 43 No. 2 connector 45 CMC adapter body 46 CMC adapter case 47 locking protrusion 48 slide piece for unlocking 49 locking piece 51 screw 53 first connector block 54 soldering terminal 55 second connector block 56 connector pin 57 Attaching terminal 61 Printed wiring board 63 Step 64 64 Ridge 65 Groove 66 Notch 67 Notch hole 69 CMC 71 Lead pattern 72 Via hole 73 Ferrite element 74 Notch hole 75 CMC adapter case, case body 76 Ridge 77 Guide groove 78 Protrusion 79 Notch 81 Screw insertion hole 82 Concave groove 83 Guide recess 84 Concave groove 85 Convex surface 88 Main body 89 Protrusion 91 Sloping surface 92 Lower surface 93 Protrusion 95 Cover 97, 98 Recess 99 Groove 101 Flat surface 102 Hole

Claims (3)

[Claims] 1. A first connector having both ends of a first connector connectable to a connector for connecting a printed wiring board unit and a cable connector, and a second connector connectable to the cable connector. A CMC adapter is provided with a CMC on a printed wiring board connecting between the first connector and the second connector, and the terminals of the first connector and the second connector are connected via the CMC. 2. A locking projection capable of engaging with a locking piece of the connector and a slide piece for unlocking are provided on the first connector side, and the cable connector is provided on the second connector side. The CMC adapter according to claim 1, further comprising: a locking piece capable of engaging with the locking projection of. 3. The printed wiring board according to claim 1, further comprising a ground pattern for connecting the shield braid of the cable to a ground circuit on the side of the device on which the printed wiring board unit is mounted. CMC adapter.