Standard Modbus Communications with MVI56E-MNET

[semilogical 0]

I have been using the MNET modules for a few years and have been successful in sending information to various Distributed Control Systems. I have a current set of projects, one being managed by EPC/Fluor and the second EPC/JGC. Both have the very same set of specifications from the end user. The first is a large system and I will use about 600 Modbus addresses in the data transfer, the EPC/Fluor group has no issues with the format: MNET_15.Data.WriteData[0] - [599], we actually have a dual setup for redundancy so the second set of info is the same only using MNET_16 as the slot designator. The second EPC/JGC expects the Control Logix to send I/O data to the 000001-099999 for Outputs and 100001-199999 for Inputs and 300001-3xxxxx for the analogs. My experience tells me the data addresses they are using would be from a PLC with a database created around a Modbus format. In the time I've been transferring information with the Control Logix I have seen no other manner of transfer using the ProSoft Technology modules. Is there anyone out there that has used a different manner of transfer format? I'm about to send a message to the EPC/JGC regarding their shortsighted desire for the transfer, I just want to be sure that I'm not being the one shortsighted.

[y2kmfic 3]

The format between 5-digit and 6-digit addressing is identical; so the MNET unit does support ant 6-digit addressing. Example.. if you tell the MNET module to send data to address 0, it will send that data to address 0, which is 40001 and 400001. If you tell the MNET module to send data to address 1000, it will send to 1000, which is 41001 and 401001. The main difference is that some devices support 65535 registers, which requires an additional digit (400001), and some Modbus devices only supported 9999 registers and don't need the extra digit. Is that what you're asking? Edited 9 Jul 2015 by y2kmfic

[semilogical 0]

Not exactly, I think I was aware of the digit difference/or non difference. The customer's EPC seems to think I can transfer my Control Logix I/O to Modbus addressing that is designated for direct inputs, i.e. if I wire ZSC-123 to Input 1 in a Modbus platform (PLC) the address is 10001 or 100001. They expect me to transfer Local:1:I.Data.0 to 100001 for their use in the DCS Control equipment. I've never heard of that even being an option. When you use the ProSoft Technologies MNET module you get to transfer the data via preset blocks that are received in the Master starting at 40001 or 400001 (as the case may be). I was just looking for someone that has experience with any alternative addressing that can be sent from the Control Logix via ProSoft.

[y2kmfic 3]

You said.. "They expect me to transfer Local:1:I.Data.0 to 100001 for their use in the DCS Control equipment." That's never going to happen since you cannot write to 1x/3x Input registers. If the MNET module was a slave, they would be able to write to 400001, which by default uses the same address space as 100001. So, if 400001 = 1, then 100001/300001 = 1. There are offsets that allow you to change this, but by default they're not used. Perhaps the EPC internal registers are similar?