Hi guys,

I'm browsing the prosoft website and find the 2 modules - MVI46-MCM & 3150-MCM. I have a project on hand use 3150-MCM.

Well as far as I (newbie here) understand:
MVI46-MCM has RJ45 port
3150-MCM has DB9

Now I'm wonderring which one is better and cheaper

Thanks for reading and your time.

By the way, has any one try to comm between SLC and MODBUS with serial port /ASCII.
So no need to use MVI46 or 3150MCM.

Is it possible or just arabian nights?

I have recently explored the options for Modbus on SLC 5/03 but yet to implement.

MVI46-MCM is a newer card with better diagnostics and more expensive than 3150-MCM.

One more option is to use DH485 to Modbus Gateway from Prosoft 5102-DH485-MCM3 if you have a DH485 port (in my case it is available). I think the advantage with gateway is that it is cheaper, it does not consume rack slot and it does not need special ladder program to map addresses unlike MVI in SLC. The gateway is provided with a simple software for Modbus to DH485 address mapping. Most probabaly I shall be going for this option.

SVN

From what I understand is the 3150 is an older model, don't know if you can even purchase it anymore. I am sure you could use a serial port to do the same thing, but for the hassle its easier to use the Prosoft card I just put 4 of them in and wasn't bad at all.

Guys thanks for your reply.

answer from prosoft:
1. The MVI46-MCM is the latest Modbus module for the Allen-Bradley SLC platform
2. The MVI46-MCM provides a DebugPort which allows the user to view module configuration and status
3. The MVI46-MCM provides a built-in Data Analyzer for troubleshooting communication problems
4. The MVI46-MCM is field upgradable
5. The MVI46-MCM is based on a 16-bit processor instead of the 3150-MCM's 8-bit processor

I'm now using MCM 3150 which costs me around 1400 usd ea.
Looking for other choice for a cost down...

The MVI-series design is used in several Prosoft platforms, which gives its application firmware a deep and wide history of being reliable. It's used in the MVI46 for SLC, MVI69 for CompactLogix, MVI56 for ControlLogix, MVI71 for PLC-5 and MVI94 for FLEX.

I strongly recommend the MVI46-MCM.

I sometimes use Modbus/DeviceNet gateways for small applications that also have DeviceNet, and I know that there are some DF1/Modbus converters that have a limited instruction set.

I've seen Modbus implemented in ladder code on the ControlLogix, and it is really difficult to install, troubleshoot, and maintain. Stick with the MVI46-MCM.