milf os
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Posts posted by milf os
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Hi Guys
Thanks for the prompt responses. I now see the error of my ways with regards trying to do both simulateously. I have since gone away from using the M91 as a modbus master and instead use a scada package to transfer values across devices.
Cheers
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Hi
I am trying to use the M91-ra22 as a modbus master and using i to poll a 3rd party device (ciat connect2 HVAC controller)
I have set up the com port initialisation and the timed polling logic to access different sections of info on the connect2.
This works fine if I'm not trying to access the M91 using the dbug function of U90. As soon as I do the connection to my laptop gets severed and I then have to reset the PLC in order to resume comms.
The polling logic is user initiated and uses cascading timers (4 of) set at 2 seconds each.
I am connecting to the PLC using a 232/485 converter to get onto the 485 bus. this works fine on its own.
Any ideas how I can access the PLC and it still poll the 3rd party device simultaniously??
Jazz R16 and Modbus RS485
in Jazz, M91 PLCs and U90Ladder
Posted
Hi
I have an 3 installations. Each consisting of
8 x Jazz UA24,
2 x M91 RA22,
1 x JAZZ R16,
1 x JAZZ T41,
4 x CIAT water Chillers
2 x PROCON analogue input modules.
They are all networked on RS485 using Specview SCADA package as MODBUS master.
All the Jazz PLCs use the JZ-RS4 com port adapter
All the Jazz controllers use the same Communication setup nets
All the Jazz controllers are run from the same 24VDC power supply
So that's the situation as it stands.
My problem is that the JAZZ R16 on all sites has very flakey coms.
It will occasionally come online after a restart for a short period of time then fall off again.
The comms on all the other devices including all the other JAZZ PLCs is pretty solid.
I have tried downloading the exact same program into a spare jazz UA24 and it communicates fine.
So by deduction I would assume it is a hardware issue with the R16 specifically.
Has anyone else had this problem and is there a way to fix it??
Thanks