Modbus timer R/W

[Aurimas]

Hello, is there a posibillity for reading and writing a timer value (not only MB or MI)?
I am using unistream 10 as a master and v700 as a slave.

[Flex727]

Of course. Can you be more specific as to what your trying to do and what you are using for communications between the two PLCs?

[Aurimas]

Thanks for the reply.
Its a Modbus TCP IP communication between Unistream 10 and V700. V700 has a timer to control the water heater not to work forewer but to stop after some time. With Unistream I am doing building management system where I have separate slaves such as air control units and 3 v700. Where to find the timer in Unistream Modbus section, I see only coils and registers, do the timers start at certain registers?

[Flex727]

In the V700, use the Function "Load Timer/Counter Preset" or "Load Timer/Counter Current", found under the "Store" drop-down menu, to place the Preset or Current value of the Timer into an MI or ML to be read by the UniStream.

The value will be in 10ms increments (e.g. 5 sec will be stored as 500). Remember that you might overflow an MI if the timer is longer than a little over 5 min or so.

[Aurimas]

Okay, so I store Timer preset for putting value into the V700 and load timer preset or currend to read it from unistream. What solution would be if my timer would need to work for like 5 hours?
And another thing, where are the ML registres in unistream modbus?
Thanks you for your help.

[Flex727]

"Load Timer/Counter Preset" is for copying the value of a Timer preset into an MI or ML. "Store Timer/Counter Preset" is for copying the value of an MI or ML into the Timer Preset. This is for Vision.

For the UniStream it's more direct. You can use the Timer Preset or Current in operations as you would any other UINT32 operand, including MODBUS address assignments.

[Aurimas]

Okay, and what about timer value over 1h?
 

[Flex727]

An ML will easily handle any timer value.

[Aurimas]

Thanks, and one more question, how to read ML from master, because I know only how to read MI.

[Flex727]

In VisiLogic, go to Help / Contents tab / Communications / Communication FBs / MODBUS IP / Slave Addressing / then click on Enhanced Vision Series & Examples. There you can read up on how to do MODBUS IP addressing in your V700.

[Aurimas]

Thank you very much !