Applicable Model(s)

OIT Models


Multiple OITs to the GE Fanuc Series 90 PLC







Multiple Maple Systems OITs can communicate to a single GE Fanuc Series 90 PLC through a CMM module. The CMM311 module is now available for the Series 90-30 PLC and the CMM711 module can connect to the Series 90-70 PLC. Each CMM module enables the user to install 2 additional ports running the GE Fanuc SNP Protocol on the PLC, and with this, the ability to connect an OIT to each port.

The Maple OIT operates in the same simple and easy fashion when interfacing with the CMM module as it does when connected to the Main SNP communication port (located on the PLC’s Power Supply Module). The user selects a separate Message Request Register in the PLC to monitor for each OIT and messages stored in each OIT are displayed according to the value placed by the PLC in each of the unique Message Request Registers. All of the PLCs registers, timers, counter and I/O as defined in the Operating Manual are accessed by each OIT connected to the CMM as if the OIT were connected to the Main Communication Port.

This means with just one CMM module and the Main SNP communications port, the user can install 3 Maple Systems OITs, e.g.:

3 x OIT3160
3 x OIT3165
2 x OIT3165 and 1 x OIT3175
3 x OIT5400

Additional CMM modules may be added to further increase the number of OITs interfacing the same PLC. Many users find the CMM is also a convenient way during development to connect both the Maple Systems OIT (through the CMM) and the GE Fanuc programmer (through Main/SNP Port) to a PLC. When development of the application is complete, simply unplug the programmer and put the OIT in the Main SNP communication port.

Serial Ports

The serial ports on the CMM are used to communicate with the Maple Systems Operator Interface Terminals. The Series 90-70 CMM (CMM711) has two serial ports, with a connector for each port. The Series 90-30 CMM (CMM311) has two serial ports, but only one connector.

CMM711 Serial Ports

The Series 90-70 CMM has two serial ports, each of which supports both RS-232 and RS-485 modes. The
pin assignments of the serial ports are identical. For use with the Maple Systems OITs, configure each port
for RS-485 and SNP communications.

CMM311 Serial Ports

The Series 90-30 CMM has a single serial connector which supports two ports. Port 1 applications must use the RS-232 interface. Port 2 applications may select either the RS-232 or RS-485 interface. Be sure to configure the Port for SNP communications when connected to a Maple Systems OIT.

A ‘Y’ cable is supplied with each Series 90-30 CMM module. The cable separates the two ports from a single physical connector. Connections to two different OITs are then possible. One OIT communicates RS-485 as it would through the single slave SNP port built into every Series 90 PLC CPU. The Second OIT would communicate via the RS-232 port utilizing a customer provided RS-232 to RS-485 converter. If the RS-232 port is used, the selected Baud Rate in the configuration setup must not exceed 9600 baud.

The following illustrates the wiring necessary to connect to the OIT Family of Operator Interface Terminals. This cable is provided by the user.

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