[TD700] Use as Modbus Master

[user10683]

I tried but always the same.

When I watch Node 1 and Node 2 sysMbMRtuNodeStatus I always have the PRES on FALSE on one PLC.

When I unplug the RS485 connector on the PLC with PRES on TRUE (the other PLC has PRES to FALSE), the PRES on the other PLC pass to TRUE.

[Pixsys tecnico 1]

Maybe is a software bug of an old release, what version of LogicLab do you have?

[user10683]

My version of LogicLab is : 3.16.0.14

[user10683]

Sorry but I don't know where to download LogicLab and PageLab ?

[user10683]

I found the last version 4.2.0.10 but always the same.

It is very very problematic

This is a very simple configuration and we change from CANOpen to modbus because CANOpen was problematic too so we need to find the bug.

[Pixsys tecnico 1]

With new version, create a new projetc instead of opening the old one.

[user10683]

It is what I did.

I did another test with IR33's of CAREL and always the same !
It is a little bit better because sometimes the seoncd one has PRES to TRUE but often passes to FALSE.

Single IR33 on the network works like a charm at modbus address 1 and 2.

Once together on the network only the first unit answers correctly the other has plenty of timeouts.

[user10683]

I did another test.

I created 2 slave devices with Modsim32 at address 1 and 2.
I connected my PC via RS485 usb to the TD700 and everything was OK (it is working like a charm no timeouts).

So there is a problem with my real network but I tested with Danfoss and CAREL devices it's the same problem !

But with Modscan32 my real network works like a charm too so I don't understand where is the problem

[Pixsys tecnico 1]

This morning I ware re-reading all messages to try to find where is the problem, I red:
"
When I unplug the RS485 connector on the PLC with PRES on TRUE (the other PLC has PRES to FALSE), the PRES on the other PLC pass to TRUE.
"

Normally this happens when the two devices have the same Address or timings are too much "short", so verify:
-slave addresses of the devices
-increase time out for esch devices to 5000mS
-increase time befor send to 20mS

[user10683]

Indeed I found the problem it was the "WAIT BEFORE SEND".

I changed everything except this parameter.
I put 300ms and everything works like a charm.

I am happy

Thank you.