Jbus to Fieldserver communication


Thread Starter


I want to communicate 90 net chloride UPS system with my PC through Fieldserver. Please let me know how to do it.

Fieldserver is a gateway, you need to have drivers for the protocols you want to interface in the gateway.

J-Bus being a variation on Modbus, any Modbus RTU driver available should handle your UPS connections. Especially if they are already linked to an existing Modbus network. (Fieldbus has a Modbus RTU driver, as advertised on fieldserver.com). You can setup your network (I think I remember that Chloride only provides a RS-232 connection on their UOPS systems, you will need to provide RS-232 to RS-485 2-Wire converter to create a Modbus multi-node network). You can test the comms using a PC-based freeware program, such as Modscan or Modtest.

In Fieldserver, once the Modbus side is ready, you will probably need to build an exchange table of sorts between the Modbus side and your other protocol.What driver will you install on the other side of the gateway? Tools for this exchange table should be provided with the gateway.

Hope this helps,
Daniel Chartier
Dear Sir,

Thanks for your reply. We are using Fieldserver FS-X40. We have installed 90-net Chloride UPS systems. Chloride have provided RS232 to RS485 converter. This RS 485 line is connected to R1 port of Fieldserver... but it is not communicating.

We were getting the data earlier for Piller UPS systems... their addresses start from 30100. Please give me your email id so that I can mail you the details.

Hello shyam;
So basically you have a Modbus RS-485 network established, but you recieve no valid data at the gateway?

1) are you getting any data at all, even if it is gibberish? This you shoud check with modsan, Modtest or any Mosbus software nyou can have access to. This will help determine if the problem is in the Modbus parameters (parity bit, for example, or data speed)

2)you seem to presume that the start address for data in the old UPS system should be the same for the Chloride system. What would make you presume that? Open the Chloride UPS mModbus manual (if you do not have that, request that urgently from your Chloride distributor), examine the Modbus mapping they offer, select the data you need to read from the units (check the appropriate modbus address the data is mapped at), and create your Modbus functions 03 or 04 so you can access the data the UPS provides, at the address they have mapped.

Hope this helps,
Daniel Chartier
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