adccommunitymod (AutomationDirect) asked a question.
Created Date: March 13,2018
Created By: simonjelly
**** This post has been imported from our legacy forum. Information in this post may be outdated and links contained in the post may no longer work.****
I have a Do-More H2-DM1E CPU in a 3 slot base with a H2-ECOM100 module installed as well. I can access the CPU for programming via either port. I can access and read the modbus MHR registers fine when using the H2-DM1E ethernet port. For example, i can query register 40010 and get a value that is in there. However, if I query via modbus using the ECOM100 port then I can get a successful read, however all registers are empty. eg 40010 will read "0 " with a successful read. Can you please advise on this issue. it appears the ECOM100 cannot access the modbus registers?
Created Date: March 13,2018
Created by: simonjelly
I have a Do-More H2-DM1E CPU in a 3 slot base with a H2-ECOM100 module installed as well.
I can access the CPU for programming via either port.
I can access and read the modbus MHR registers fine when using the H2-DM1E ethernet port. For example, i can query register 40010 and get a value that is in there.
However, if I query via modbus using the ECOM100 port then I can get a successful read, however all registers are empty. eg 40010 will read "0 " with a successful read.
Can you please advise on this issue. it appears the ECOM100 cannot access the modbus registers?
Created Date: March 13,2018
Created by: franji1
The ECOM100 Modbus implementation is a DirectLOGIC implementation, hence it utilizes the old 205 Modbus to DL map. There is a spreadsheet somewhere that shows how all that works for a DL PLC. Therefore, since the ECOM100 maps Modbus reads/writes to DL type memory, it will show up in Do-more's DL mapped memory, specifically DLC, DLX, DLY, or DLV. The Holding Registers end up in DLV somewhere (note that Modbus addresses are in decimal, DL memory is octal). The spreadsheet will show you where HR 40010 in DLV memory.
Created Date: March 13,2018
Created by: kewakl
The ECOM100 Modbus implementation is a DirectLOGIC implementation, hence it utilizes the old 205 Modbus to DL map. There is a spreadsheet somewhere that shows how all that works for a DL PLC. Therefore, since the ECOM100 maps Modbus reads/writes to DL type memory, it will show up in Do-more's DL mapped memory, specifically DLC, DLX, DLY, or DLV. The Holding Registers end up in DLV somewhere (note that Modbus addresses are in decimal, DL memory is octal). The spreadsheet will show you where HR 40010 in DLV memory.
As such, I guess that the domore's modbus security scheme is bypassed.
Created Date: March 13,2018
Created by: Do-more PE
As such, I guess that the domore's modbus security scheme is bypassed.
Nope. DL memory is sandboxed just like the Modbus memory.
Created Date: March 13,2018
Created by: kewakl
Excellent!
Created Date: March 13,2018
Created by: BobO
In addition to security concerns, the sandbox approach also allowed us to match the native addresses of whatever we were talking to, including radix, eliminating translation tables and the associated customer confusion. So V1400 actually targets DLV1400, which is also octal.
One of the common issues customers face when using Do-more, particularly DL users, is that Do-more is much simpler than they realize. A big part of the learning curve is learning what they *don't* need to do.