adccommunitymod (AutomationDirect) asked a question.
dl06 -dl05 modbus error
Created Date: October 16,2005
Created By: eet2002
**** 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 Information in this post may be outdated and links contained in the post may no longer work.****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 dl06 (master) talking to a dl05 (slave) via modbus (3 wire rs232 9600 baud). Everything works fine until I turned the dl05 from term mode to run mode. The dl06 then reports exception reponse error of "slave device failure ". all ladder comms are interlocked, SP116 etc. tried changing dl05, different port on dl05, different baud settings and checked all wiring connections, grounds etc. Can anyone help please
Created Date: October 16,2005
Created by: bcarlton
I haven't tried this particular move. I always run my units in 'term ' mode. But, is this similar to the lockout of HMI changes which happens when you go to 'run ' mode? Maybe it must be left in 'term '.
Created Date: October 16,2005
Created by: eet2002
Is there any adverse effects of leaving the PLC in Term mode. On page ch4/7 of the user manual they issue a warning of leaving the PLC in Term mode when the PLC is powered down for an extended period. The application I have in mind will always be powered up, so should never have a problem. But Murphy's law says otherwise.
Created Date: October 17,2005
Created by: Tech Guy
There really isn't much difference in leaving the unit in "term " vs "run ". I have always left units in the "term " mode and have never had a problem.
Created Date: October 17,2005
Created by: Tom Jenkins
On a number of different ADC PLCs I have had a lot of comm problems between PLCs and between the PLC and an HMI when the switch is in RUN. This is true with both DirectNET and K-Sequence protocols. We normally leave the PLC in TERM and have only had one or two instances over the years with the PLC not coming back with the program running after a power cycle.
Created Date: October 17,2005
Created by: Tech Guy
I also meant to say that in some DirectLogic PLCs the communications ports are disabled while the switch is in the "run " position.
Created Date: October 17,2005
Created by: franji1
Have you tried DirectNet protocol instead of Modbus? It looks like you are doing point to point with RS232.
It may work with DirectNet??? (I'm grasping here, but just a thought).
You may need to change your RX/WX instructions since the slave addresses will be native instead of "mapping " them to their "Modbus equivalent " (e.g. V2000 is V2000, not 40123 or whatever).
Created Date: October 16,2005
Created by: eet2002
I have a dl06 (master) talking to a dl05 (slave) via modbus (3 wire rs232 9600 baud). Everything works fine until I turned the dl05 from term mode to run mode. The dl06 then reports exception reponse error of "slave device failure ". all ladder comms are interlocked, SP116 etc. tried changing dl05, different port on dl05, different baud settings and checked all wiring connections, grounds etc. Can anyone help please