Oja,
I've the same problem with a genset controller, and i've found a walk around:

• Create a new data source for your modbus slave with just one point (the write only register) and without slave monitor points.
• Disable point read exception alarms
• Use an update period of 9999999 hours (it'll bother just at first update, never alarm again 'cause next update will be at 10 years ;))

You need to create a new data source because you need to receive point read exception alarms from all the other read and read/write points on your modbus slave.

Best regards,

David Parra

Attachment: download link

You're right. USB-Serial adaptors aren't the most compatible peripheral in the world.

But my problem is different, 'cause i use a Serial to Ethernet adaptor (Moxa calls it "device server"). If i install a driver on my PC, i got a virtual COM port though ethernet.

When i use modpoll for test (www.focus-sw.com/fieldtalk/modpoll.html) everything works:

D:\>modpoll -m enc -r 8196 -1 -p 4001 *MyIPAddress*

modpoll - FieldTalk(tm) Modbus(R) Polling Utility
Copyright (c) 2002-2006 FOCUS Software Engineering Pty Ltd
Visit http://www.modbusdriver.com for Modbus libraries and tools.

Protocol configuration: Encapsulated RTU over TCP
Slave configuration...: Address/Id = 1, start reference = 8196, count = 1
Communication.........: *MyIPAddress*, port 4001
Data type.............: 16-bit register, output (holding) register table

Polling slave ...
[8196]: 226

But i can't select "Encapsulated RTU over TCP" on Mango (AFAIK, this protocol is supported).

I try to configure an Modbus IP data source without luck.
Transport Type: TCP
IP: MyIpAddress
PORT: 4001

jkyner says:

also works fine with the Moxa 5130 (a basic Ethernet/RS485 SDA that is not Modbus-aware) for those Modbus slaves that can handle the 6-byte Modbus TCP-RTU header forwarded over RS485.

Therefore... My Modbus slave is incompatible with mango?

Thanks a lot!!

David Parra

@mlohbihler said:

Hello Tomas,

Mango already supports Modbus RTU over TCP and UDP.

I try to configure a gen-set controller without success.

Testing with modpoll using "Encapsulated Modbus RTU over TCP" works fine, but i can't do it with Mango.

AFAIK, RTU over TCP uses a header different than Modbus/TCP. I need a new data source type? I try with Modbus IP without sucess.

Best regards,

David Parra

I've a gen-set controller with modbus/RTU connected to a Moxa adapter.
modpoll (http://www.focus-sw.com/fieldtalk/modpoll.html) works great for test using "Encapsulated Modbus RTU over TCP", but i can't get it running on Mango.

It's possible to get this device works with Mango?

Regards,

David Parra