I have a DL06 controlling liquid addition system, and I need to pull the status of an output out of a Modicon Quantum PLC. I am using a HO-ECOM100 card for ethernet communications. I have never done communications between two different manufacturer's PLCs. What would an example rung look like to check bit status of an output 00590 in Modbus?

WestRN at Cormetech. com

 

You need an OPC driver in order to communicate with QUANTUM via Ethernet or easier you may use serial port RS232 Modbus RTU integrated in both PLC (DL06 and Quantum). You can decide which one would be the master indifferently.

To read the output 00590 you need to know the Modbus address that I suppose would be 000590 (DL06 should have a modbus memory map..).
If Quantum was the master you would use XXMIT function in the Unity Pro communication library (CPU version greater than V2.3) or XMIT with old Quantum by using Modsoft/Proworx/Concept.

If you are more familiar with DL06 PLC it is better to use its dedicated modbus function.

 

Move the coil in the Quantum to a 4x register in the Quantum with a BLKM or SUB instruction for 984LL, use a bit_to_word for IEC. Move the 4x register in the Quantum to an unused V memory location in the DL06. You have to use the Ethernet I/O scanner or an MSTR instruction in the Quantum to do that. The DLO6 Ethernet module documentation has a table that shows the mapping of Modbus 4x registers to DL06 memory. The DL06 doesn't have an instruction to a move word to bits, instead it uses overlapping address. Read section 5 of HX-ECOM-M manual to find a memory area that you are not using where the DL-06 V memory is mapped to Y memory. Add a contact to coil rung in your DL-06 program to copy this bit to an I/O mapped coil.

 

We checked the settings in the Quantum and found that the I/O scanner function was not being used. I believe the v memory location on the dl06 is 40000 for the Modbus communication the mstr instruction was very helpful but we still have a couple of bugs to work out. Is it best to use the ECRX boxes for these types of functions?