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PLC 'Serial Gateway' To The Inverter

This tutorial is intended as a supplement to the original manuals for the products. Therefore, use it to familiarise yourself with the product and not as a guide for complete installation.
The information in the tutorial is taken from following manual (s):
W336 Sysmac CS / CJ Series SCB / SCU Operation Manual
Serial Gateway
The new version of firmware (Ver. 1.2) to the SCU / SCB card allows you to use the optional serial port as a 'Gateway'. This means that you can go through the PLC from a connected device on a port to another device connected to another port (green dotted line). This tutorial illustrates how you can get the connection between a PC, which is connected via serial
online to the PLC (blue line), and an inverter which is also connected to the PLC serial (red line). The PC is connected to any serial port that uses the Host Link or Toolbus as a communication protocol. The inverter (e) is connected to a serial port on an SCB / SCU card which is set up to the 'serial gateway'.
When using this form of communication, the settings for Modbus 'slaves' and 'master' (SCU / SCB card) must be identical. For Modbus  9600, 8, N, 1 is widely used, but other settings can be chosen. The setting must be changed for each number of slaves. These are set to 0 in the factory but must be at least 1 in this instance. The tensions must be resolved before the changes to the slaves settings take effect.

To enable the PLC to talk to the slaves when the PC can not you must change the mode setting of the relevant port on the
SCU / SCB card. When the PC should have control, the port must be set to 'Serial Gateway' and alternatively to  'Protocol Macro' when the PLC is in control.  For PLC control, you must also program the SCU / SCB card with a Modbus Master protocol, and the PLC 
with PMCR instructions. Changing the controller must be done manually.

From the icon in the CX-Drive a window appears to the left. Select here
Connection Type = Via PLC (SCU / SCB).
Under settings (Settings-Network) select any the Modbus slave
you want to connect to (Slave Unit Address), and the port on the SCU / SCB card 
that it's connected to(Port Selection). You must also specify the address setting
(UNIT No.) for the SCU / SCB card in the front (Master Unit Address).
Under Settings-Gateway PLC set the
communication type between PC and PLC.
These settings are similar to those in the CX-Programmer. For serial
communication it is important to choose the right serial port on your PC.


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Created 2008-11-19
Modified 2009-04-02
Views 8606


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