Parker Hannifin
home | products | how to buy | support & downloads | literature | search

Click Here to go to new EM&D Knowledge Base (FAQ) site

How to Add ModbusTCP to PAC project (PAC as ModbusTCP slave)

Related FAQ:  Using the PAC as a Modbus TCP Master Device

Related FAQ:  Using the PAC as a Modbus TCP Slave Device


1. Within Parker Automation Manager Integrated Development Environment (IDE) software, under Device (PAC320...) right-click to Add Device...

2. Under Ethernet Adapter, select Ethernet (3S):


3. After adding to project, right-click on Ethernet and select Add Device...

4. Under Modbus > ModbusTCP Slave Device, select ModbusTCP Slave Device:

5. On the ModbusTCP tab, Configured Parameters, uncheck TimeOut

If not, the PAC inputs (parameters and bits) can change after 2 seconds of a Timeout.

Default is 10 Holding Registers (inputs from PAC to Modbus Master) and 10 Input Registers (outputs from PAC to Modbus Master).

Minimum is 2 for each.

6. In the ModbusTCP Slave Device I/O Mapping tab, set the Always update variables to Enabled 2 (always in bus cycle task) and set the Bus cycle task to a slower task (not the EtherCAT_Master task which is the only task defined as default.) This task should be on the order of 20ms or slower depending upon the application requirements. Enabled 2 was added to SP5; update PAC software if this isn't part of the pulldown.

7.  Now you're free to select Modbus TCP Slave Device I/O Mapping tab to name your Inputs & Outputs.

Each Word is 16 bits. Each Word can be named or you can name each of the bits.

Double-click on the line and type Application. Note that it types forward. With typing Application and then '.' it will list variables you can map to.

Or you can click the ... on the right side (or press F2) to launch the input assistant. Here, searching GVL shows variables from the project's Global Variable List.

Alternately, you can import & export device names from a .csv file.

Select ModbusTCP and on the PC tower icon and right-click:


The above uses an Parker Interact Xpress XPR2 panel with its IP address set to similar network (192.168.10.xx subnet

A sample Xpress project is available here:


Note this is different than the sample in the QuickStart FAQ that is a newer version using the embedded Xpress option for the PAC with the PAC Terminal.