MXPA99002836A - Connector for programmable logic controller having modifiable termination therefor - Google Patents

Abstract

A connection scheme for a Programmable Logic Controller is taught. Briefly stated, a printed circuit board having a plurality of electrically conductive traces therein and a plurality of electrically conductive fingers associated with the conductive traces is disclosed. The pitch and size of the conductive fingers coincide with that of a PLC I/O connector. One or more of a plurality of interconnective devices may be connected to the printed circuit board thereby minimizing adverse thermal effects from adjacent thermocouple wires or providing for use of various interconnection devices or signal conditioningsuch as switches, displays, discrete devices and the like.

Description

CONNECTOR FOR A PROGRAMMABLE LOGIC CONTROLLER THAT HAS A MODIFIED TERMINAL FOR THE SAME FIELD OF THE INVENTION This invention relates, in general, to connectors for programmable logic controllers and more particularly to a connector having means for physical and / or electrical conditioning or input cables.

BACKGROUND OF THE INVENTION Programmable Logic Controllers (PLCs) are being used more and more frequently as their cost and size decrease. This increase in use is also due to the increased functionality, while at the same time a dramatic increase in the number and types of operating systems with a PLC can cooperate with programming tools, which widely facilitate writing appropriate sets of instructions. Therefore, it is likely that PLCs once installed will be modified or adapted on the flight with, for example, new operating instructions, additional input / output instructions (1/0) and signals, particularly instrumentation. As a result of these PLCs, they are being used in many more applications. Although many types of inputs are commonly connected to PLCs, one of the most frequent is from the analogue instruments, the most frequent being the thermocouples used for temperature measurement. However, also increasing in use are the analogue inputs of devices such as tank gauges. However, it is common that these types of devices are analog and, particularly in the use of thermocouples, produce or dissipate heat. However, since these inputs are analog, anything that affects the input of the transducer, or the inputs of the adjacent transducer may result in inaccuracy. Therefore, this inaccuracy can be either accepted or compensated in such a way that the program in the PLC can operate properly. It is generally known that the acceptance of inaccuracies only acceptable in only the most limited of situations. Therefore, designers are left with the solution to predetermine what those inaccuracies and comps are. Another problem associated with PLC inputs is that users usually have a choice of analog or digital inputs which are not definable even if they are operated by the machine. While this typically does not present a problem in the initial and implicit design, it is problematic when the instrumentation is changed or aggregated. There, the user must condition the instrumentation at its point of use since, that is an analog signal that must be digitized if only the digital inputs are available in the PLC. In the same way, the opposite occurs with regard to PLC outputs. Also, due to packaging constraints, particularly, in the new "brick" size of the PLC, the connector for in-row connections at 11 da (I / O) occupies all the usable space at the front of each module. This leaves very little or almost no space for several other elements such as switches, logic connectors, potentiometers, fuses or operator input elements. This problem of size is particularly acute due to the thermal variations between the upper and lower portions of the connector due to thermal transfer between the contacts of the connector and the module or the PLC. It is known that in order to precisely design the thermocouple PLC modules, the reference thermocouple wires must be kept relatively the same temperature across their length in order to maintain a stable and consistent junction temperature. Therefore, the deformation of thermocouple wires or the simple use of simple analog cables with thermocouple wires often results in very poor thermal characteristics., which give the upper contacts much much higher temperature reading than in the lower contacts. EP-A2-0 599 362 discloses a multi-point connector element having a slot and pin device for preventing disengagement of the plug and socket elements. Accordingly, it is desirable and it is an object of the present invention to produce a device which minimizes the thermal gradients between the different portions of the contacts of ./O. It is also desirable and an object of the present invention to produce a device which allows the use of additional components adjacent to the PLC such as, potentiometers, switches, displays, other types of connectors and the like. Still another object of the present invention is to produce a device which allows the signal conditioning inside or outside the PLC. Finally, it is still another object of the present invention to produce a connector for use with a Programmable Logic Controller (PLC), comprising an inferring connector board consisting of a plurality of conductive paths therein, the inferring connector board having an edge and a flat surface arranged at an angle with respect to the edge; a plurality of contact conductive fingers, which are spaced apart from that of such conductive paths, each of which is connected to at least one of the plurality of conductive paths, the plurality of conducting fingers arranged along the edge of the inferring connector board; and at least one secondary inferring device arranged on the planar surface, the secondary inferring device electrically connected to at least one of the plurality of conductive paths contained in the inferring connector board.

BRIEF DESCRIPTION OF THE DRAWINGS Reference can now be made to the accompanying drawings in which: Figure 1 is a schematic representation of the interconnection scheme according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to Figure 1, a schematic representation of the interconnection scheme in the present invention is shown. More particularly, a programmable logic controller (PLC) 10 shown in an imaginary manner is shown. It should be understood that any type of PLC can be used without departing from the spirit and scope of the present invention. For example, PLCs may be of the S7 type produced by Siemens Energy & Automation, Inc., of Atlanta, Georgia. Associated with the PLC 10 is an input / output connector block 11 (I / O) of the PLC 12. It should be understood that the connector block 12 in the preferred embodiment of the present invention is the connector diagram provided by the manufacturer of the connector. PLC. However, the connector block 12 pu may be an intermediate connector block which provides different contact sp eaces between the PLC and the end of the connector scheme. Associated with the connector block 12 are a plurality of PLC I / O contact points 14, with the number, size and spa c i ami at (separation) depending on the specific PLC. Shown adjacent to the connector block is the connector board of infer 16 according to the preferred embodiment of the present invention. In the preferred embodiment of the present invention, the inferring board connector 16 is composed of a printed circuit board (PC) 20 which can be any suitable or desirable type such as, for example, single layer or multiple layer and of accommodated surface mounted and / or laminated through the component assembly. Arranged along one edge of the PC board 20 are the laminated fingers 18. The size, number and spacing of fingers 18 is configured in such a way that it corresponds to the contact points 1/0 PLC 14 associated with the PLC. Further, although the rolled fingers 18 are shown, it should be understood that the discrete contact fingers (not shown) can be welded with any acceptable means on the edge of the PC board 20 in order to provide contact fingers. Arranged on the PC board 20 there is a plurality of interconnection devices. Included are an inverted switch or switch 22, a connector 24 (which may be of the screw termination or friction adjustment type such as a zero or low insert, ZIF / LIF connector), a display device 26 , a D-type connector 28 or a discrete component 30. It should also be understood that the discrete component 30 may be one or more passive or active components or a combination thereof. Connected to the connector 24, there are the thermocouple wires 32 which go to the equipment (not shown) cooperating with the PLC 10. In this way it can be seen that the use of the connector board of infer 16 allows more space between the points of adjacent connection, while also allowing uniform distribution between thermocouple wires. It has been found that this greatly minimizes excessive or undesirable heating of the thermocouple wires. Additionally, it allows the substantial increase in dielectric insulation between adjacent contacts. In addition, it allows the user to easily adapt a plurality of methods or components of interconnection, thereby allowing the conditioning of the signal such as, for example, the conversion of AD or DA, the appropriate gain or levels of impedance and the like, without having than using different combinations of PLC I / O which can not yet be available by the manufacturer. It should be understood that many variations of the present invention can be practiced without departing from the spirit and scope of the present invention and the scope of protection will be limited by the appended r e i i i i n i hereafter.

Claims (9)

1. A connector for use with a Programmable Logic Controller (PLC), comprising: an inferno connector socket, consisting of a plurality of conductive paths therein, the bottom connector board having an edge and a flat surface disposed at an angle with with respect to the edge; Thus, a secondary infernode disposed on the planar surface, the secondary inferiode device electrically connected to at least one of the plurality of conductive paths contained in the inferring connector board; characterized by a plurality of contact conductive fingers at a spacing which is different from that of the conductive paths, each of the conductive fingers are connected to at least one of the plurality of conductive paths, the plurality of conducting fingers are arranged along the edge of the connector board of i.

2. The connector for use with a Programmable Logic Controller (PLC) according to claim 1, wherein the inferring connector board is composed of an impregnated circuit board.

3. The connector for use with a PLC according to claim 2, wherein the conducting fingers of a plurality of contact members are composed of laminated portions of the printed circuit board.

4. The connector for use with a PLC according to claim 2, wherein the conducting fingers are composed of a plurality of contact members.

5. The connector for use with a PLC according to claim 1, wherein the secondary inferring device is composed of at least one of the groups consisting of: a mechanical or electromechanical switching device; a block with a screw type terminal; a connector block of the friction adjustment type; a device visualize; a subminiature connector type D; an electrically passive device; an electrically active device.

6. The connector according to claim 5, wherein the electrically passive device is at least one of the group consisting of: capacitor; resistor; inductor

7. The connector according to claim 5, wherein the mechanical or electromechanical switch device is at least one of the group consisting of: relay; inverted switch; jogger switch.

8. The connector according to claim 5, wherein the electrically active device is at least one of the group consisting of: an operational amplifier; a digital logic device; a semiconductor device; a memory device; a device my cr or c e s.

9. The Programmable Logic Controller, comprising the connector of the indication 1, and further comprising an I / O interconnect connector having a plurality of discrete connection points and wherein the plurality of conducting fingers is at a distance which it is comfident with that of the plurality of discrete connection points of the I / O interconnect connector.