Jazz - Master ad Slave Modbus

[Wojtek]

Hello,

Short description of our installation:

Basis on JZ10-11-T40 with JZ-RS4 RS232/485 we controll humidty and temperature in 5 rooms.

In each is installed modbus transducer working as Slave.

We can program set points and all necessery data trough keypad, but client want to extend system.

He wants to connect it to Scada, InTouch, and now starts problem.

Is it possibile at all? As Scada is always Master and Jazz has to be Master for reading data from transducer.

We have idea to set Jazz for reading data as Master every 30 sec ( done by timer ) and them back for Slave awating for Scada to read data from Jazz.

Can we got an answer if something like this is possibile?

[Emil]

Hi Vojtech,

In the matter you describe Jazz has even advantage compared with Vision. In Jazz, when you set the port as Modbus, you "automatically" set it as Slave. Then, you perfomr Modbus command and it acts as Master.

Based on that, there is no special need to switch between Master and Slave there.

Where can be the conflict? If the SCADA is perfming communication with Jazz, it can be busy to perform Master command.

Workaround idea:

When switching between Master and Slave, to change ID of the unit. In this case SCADA will not connect and Jazz needs ot be free to connect to its Slave.

In this case the SCADA will loose communication for some times.

The idea is not checked here - it's just idea.

If you're going to try it, please let me know the result.

[Wojtek]

Hi

I do like your answer very much.

Of course we will try and will inform you of the results.

We will try our idea too, but generally will follow easer way ( your).

thanks

Wojtek