Hi,

Can any one tell us, how to read and write the addresses via Ethernet from SLC 5/05, where i connected Carrier make chiller to etherent network (By using a Modbus to Ethernet converter) i used AB SLC 5/05 which is connected to the same network.

Thx
N.Subrahmanyam

Pardon these questions, but we need to better understand what you need.

You have an SLC 5/05 and want to communicate with it over ethernet, but you don't specify from what? Another PLC, a PLC or some proprietary controller?

What part does MODBUS play in all this plan of yours?

Though it doesn't really give a lot more information I believe he is saying that it's a "chiller" made by Carrier.

Hi,

Thanks for your reply any how i will explain briefly as below

I have SLC-5/05 connected to switch, and further to SCADA station RSview, i have a third party devise that is Carrier make Chiller with Modbus it needs to be controlled from SCADA station i.e. reading process values and writing set values and on/off of chiller, for that i am planning to connect the chiller by using a Modbus to Ethernet converter so that i can connect chiller to switch via this converter but now how can i do the programming in RSL500 please suggest if you have any idea.

I know it can be done by using a ML1100 or Prosoft please tell me if any other method is there

Thx

N.Subrahmanyam

You need to determine exactly what physical and protocol interface the chiller supports. Physically, it could be RS-232 or RS-485 or Ethernet. The Protocol could be Modbus RTU or Modbus TCP, and it could be a Master or a Slave. I suspect that it is most likely an RS-232 Modbus RTU Slave, but that's a guess.

The Digi One IAP device is probably the least expensive and simplest method for converting from the SLC-5/05's EtherNet/IP protocol to Modbus RTU protocol.

Some users have reported difficulty configuring the Digi One IAP for the first time. It's not a complex device, but it is a complicated device.

You might call Real-Time Automation and ask if their EtherNet/IP to Modbus RTU module is compatible with SLC-5/05 "EtherNet/IP Explicit Message" EEM instruction messaging. They have a very good reputation for being very easy to configure.

I automatically started thinking of your application as being an SLC -> Chiller communications path, but you can much more easily connect RSView to the Chiller directly using a software component that supports Modbus, like KepServer.

It is possible to do Modbus/RTU via the serial port. It's not easy because you will have to write your own code to do it. Go to www.modbus.org and download and read the protocol specification.

Making it an Ethernet signal is a very bad idea normally. You cannot speak any protocols except Allen Bradley proprietary ones via Ethernet and Allen Bradley PLC's, at least directly.

If you try any other method, you are going to have to use a protocol translator such as Digi One IAP, a Prosoft module, or ML1100. For the money and the ease of use, ML1100 is probably actually the easiest method, next to hand-coding commands to use the serial port on the SLC 5/05 to read/write Modbus commands.