3150-MCM to ViscoScope meter

Hi people,

I have four prosoft 3150-MCM cards talking to slave devices via RS485 everthing is great. PLC SLC500 ladder code doing what it should polling the devices collecting the data. However, now that a new device has been added which should be using the same modicon protocol to a new 3150-MCM card in a new SLC500 PLC the existing code does not work. The original cable set up has been used and checked but the yellow error light just will not go away. The device in question is a ViscoScope Viscosity meter it's manual, (which I can send to anyone who is interested, talks about sending byte information whilst the prosoft code sends words. This is very confusing as I have done the command list in various configurations without any success. If I could just get the error light to go out then it's the command list to sort out to get the information requested from the commands I send.

So has anybody come across the ViscoScope device and actually found away of talking to the damm thing. Actually could be the cable setup?

Any help would be gratefully received.

Thanks