JPS5917641A - Device for switching program of programmable sequence controller - Google Patents

Abstract

PURPOSE:To select a different program easily and to make the titled device correspond to various requests, by providing an alternation switch which selectively switches a chip enable line of an EPROM. CONSTITUTION:Plural EPROMs 5a-5n having different programs respectively are arranged in the same address space of a subboard of a programmable sequence controller. When the programmable sequence controller requires a program stored in the 1st EPROM 5a e.g., a chip enable line 4a of the EPROM 5a and a program of the EPROM 5a is selected by contacting a movable contact of an alteration switch 15 with the 1st fixed contact 16a. When a program stored in another EPROM is required, the movable contact 17 of the alteration switch 15 is brought into contact with a fixed contact connected to the chip enable line 4n of an EPROM 5n e.g. in which the required program is stored, so that the required program can be easily selected.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is used in a programmable sequence controller that stores logical operation instructions in advance in a storage device C2, sequentially scans these instructions, processes input signals, etc., and outputs them. This invention relates to a program switching device.

Conventionally, the instruction storage section I of a programmatic pull sequence controller has two methods: one uses a battery-backed RAM, and the other uses an IPROM or the like in which instructions are written in advance without using a battery. In the former case, since it is a FLAM, it is possible to change the program at any time, but on the other hand, it takes a lot of time to maintain the battery. In the latter case, since no battery is used, no maintenance is required, but since RPfLOM is used, it is difficult to change the program. When an EFROM is used, the control of a dedicated machine is mainly used, so once the program is fixed, the program will rarely be changed thereafter.

FIG. 1 shows a conventionally known lPROM.

In this figure ≦2, the code 5 indicates the RPltOM main body, and 1
is its address line, 2 is its data line, 3 is its control line, and 4 is its chip enable line.
When set to v or low, EFROM5 is selected and becomes accessible. 6 is a power line.

The agpaoM has a storage capacity of 2 bytes or 4 bytes, and is often used from address 0, and up to 2K or 4 bytes of the sequence control program are written from address 4o. Among them, (= contains a series of sequence control programs consisting of one or more programs.

By the way, if you want to change the program, you have to turn off the power to the controller and replace the gP ROM, which takes a lot of time and effort. Also gPfL
By increasing the address space of OM, it is possible to mix various programs, but on the other hand, it increases the number of logics such as address decoding, which has the disadvantage of not being cost-effective.This invention eliminates these conventional disadvantages. An embodiment of the present invention will be described below with reference to the drawings. Note that the description of the same parts as shown in FIG. 1 will be omitted.

The sub-board 11 of the Snawachi programmable sequence controller [2 is a plurality of gpaovs a, 5 b, etc. each with a different program]
5n is allocated to the same address space. Further, a connector 12 is attached to the sub-board 11, and this connector i2 is provided with an EPROM15I (socket) 14 for supplying signals via a cable 13. Furthermore, a changeover switch 15 is attached to the C Nisubboard 11. A plurality of fixed contacts 16 of this changeover switch are provided, and each is electrically insulated from each other.

These fixed contacts each have EPf'LOM5a, 5b...
......5n chip enable lines 4 are connected. Also, the movable contact 17 of the changeover switch 15
are in selective contact with each fixed contact 16. Therefore, when the programmable controller requires a program stored in gPROM 5a of IJl in FIG. By bringing the contact 17 into contact with the first fixed contact 16m (2), the chip enable line 4 of the first BP 0M5m is selected, and thereby the first E!
The program in ROM 5m is selected.

When a program stored in another gPfLOM is required, C: connects the movable contact 17 of the changeover switch 15 to the EPRO in which the required program is stored.
M, for example, 5nC, can be easily selected by touching the fixed contact 16n connected to the chip enable line 4nE.

As described above, this invention arranges a plurality of EPROMs each having a different program on a sub-board forming the same address space, and also
Since a changeover switch is provided to selectively change over the chip enable line of OM, different programs can be easily selected in one Progera Y pull sequence controller, and therefore various demands can be met. In particular, it has the advantage of being able to obtain results with high loss of force.

[Brief explanation of drawings]

Figure 1 is a plan view showing a conventional EFROM, Figure 2 (5)
2 is a plan view showing an embodiment of the present invention, and FIG. 3 is a plan view of the main parts. 1...Address line, 2...Data line, 3I
-9 control line, 4...chip enable line, 5
・Suga・BPFLOM, 6...Power line, 11...
Sub-board, 12... Connector, 13... Cable, 14... Socket, 15 River selector switch, 16...
... Fixed contact, 17... Movable contact. Patent applicant Yamatake Hachinewel Co., Ltd. Agent Patent attorney 1) Hiroshi Sawa Showa 1i'l Same
Right horizontal Akio 40~
(6)

Claims (1)

[Claims] In a programmable sequence controller that uses EP1'LOM as a program storage element, a plurality of EFROMs each having a different program are arranged on a sub-board forming the same address space. A program switching device for a programmable sequence controller equipped with a switch that selectively switches between two lines.