Author Topic: How to expand Analog I/Os?  (Read 10291 times)


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How to expand Analog I/Os?
« on: March 19, 2003, 08:57:23 PM »
The M-series PLC has fixed 8 analog inputs or 6 analog inputs and 2 analog outputs and is not expandable.

However, since all M-series PLCs have built-in RS485 port, you can easily use it to connect to RS485 based analog I/O boards. ?For example, you could use another low cost T100MD888+ to add another 8 analog I/O (plus many other functions, of course), or you could use a 3rd party analog I/O board to give you different selection of resolutions and voltage/current interface.

We have thoroughly tested two units of the I-7000 modules made by ICP-DAS. One of them is a 16-bit, 8 channel analog input module, ?and the other is a 2 channel, 12-bit analog output module that support 0-10V, 0-20mA or 4-20mA. Both modules proved to work readily with the M-series PLC via the RS485 port. We have written an application note and some sample .PC5 programs for working with these modules. They can be downloaded from the following link:

Multiple units of I-7000 can be multi-dropped from a T100MD+ or MX+ PLC, allowing hundreds of analog I/Os to be connected to a single PLC. Since the PLC can also be a MODBUS slave this can also serve as an ultra low cost RTU subsystem.

ICP-DAS also have other modules that may be of interest to M-series PLC users. These include one that connect up to 8 channel of thermocouple input directly (model I-7018). That means no need for expensive signal conditioners! Just plug the J,K or other types of thermocouple to the module's inputs, connect up to the PLC's RS485 port and instantly the PLC will be monitoring up to 8 temperature zones. ?There is also a 4 channel analog output module for those who needs lot of D/A outputs.
To find out more about the I-7000 modules and their prices, please visit:

« Last Edit: December 31, 1969, 04:00:04 PM by -1 »
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