-Operating System: Windows 10

- TIA Version : v14 SP1

- Hardware Modules numbers : s7-1200

- The desired application :

I want to call two instances (sequentially) of the MODBUS_CLIENT FB with two different adresses, into the same FB container;

To do that, I structured my program to do the following steps (I will call the different instances M1 and M2 for clarity):

• keep to true the M1.REQ signal for the first MODBUS_CLIENT FB instance;
• I wait for a M1.ERROR or M1.DONE signal by this instance;
• When I receive a M1.ERROR or M1.DONE signal, I keep to true the M1.DISCONNECT signal for 1 second and put M1.REQ to false
• After that, I put to true the M2.REQ signal 
• When I receive a M2.ERROR or M2.DONE signal, I keep to true the M2.DISCONNECT signal for 1 second and put M2.REQ to false

• both the MODBUS_CLIENT FBs are always enabled inside the FB container

- The Problems (Bugs) :

It works for few minutes, and I read correct information, but after some time I get error state 16#80A3 or some others similar error codes;

- Expected causes of the Problem :

I think that the problem is in some global variables used from the MODBUS_CLIENT function block; Is there something like a "flush" that I can do to reset the MODBUS_CLIENT function block instances between the two calls? Or some other solution? I have tried to also work by alternatively disable the EN variable on the instances, but I obtain that only one of the instances work correctly and arrives to the 16#7004 state

Please help!  Thank you

 Thank you for your reply; I just tried; Doing this, only one of the two instances works, the other don't

Denilson Pegaia

Hi,

did you tried to use the same instance DB, and enable the block calls one per time?

nelloug

 Thank you for your reply; I just tried; Doing this, only one of the two instances works, the other don't

Denilson Pegaia

Hi,

did you tried to use the same instance DB, and enable the block calls one per time?

Consider sharing some code with the Forum. Perhaps as a PDF printout.

 No problem, I would be grateful if you can help me; Here is my code; The #connection is the same for the two instances, because I have to read two different areas from a SentronPAC

#dP

 

nelloug

 Thank you for your reply; I just tried; Doing this, only one of the two instances works, the other don't

Denilson Pegaia

Hi,

did you tried to use the same instance DB, and enable the block calls one per time?

Consider sharing some code with the Forum. Perhaps as a PDF printout.

Hello,

in my opinion one problem can be (due that STATUS 16#80A3) in not correct handling disconnect from Server. I see not correct procedure as wait 1s and then making some other sequence, here i see correct procedure set DISCONNECT and check instance/static TAG Connected. then you can proceed to next sequence.

 Thank you I'll try to implement your suggestion in the afternoon

Duris_I

Hello,

in my opinion one problem can be (due that STATUS 16#80A3) in not correct handling disconnect from Server. I see not correct procedure as wait 1s and then making some other sequence, here i see correct procedure set DISCONNECT and check instance/static TAG Connected. then you can proceed to next sequence.

 I just tried to modify my code as you suggested; No improvements, still randomly one of the two MB_CLIENT gives error 80A3

nelloug

 Thank you I'll try to implement your suggestion in the afternoon

Duris_I

Hello,

in my opinion one problem can be (due that STATUS 16#80A3) in not correct handling disconnect from Server. I see not correct procedure as wait 1s and then making some other sequence, here i see correct procedure set DISCONNECT and check instance/static TAG Connected. then you can proceed to next sequence.

 

Hello,

look, this is only improvement to your code in case of this error occured. In case of 80A3 it can be also f.ex. re-establsih existing connection or already mentioned attempt to terminate not existing connection. Other (first general problem) can be using of same connection ID with parameters for both blocks, now I'm only think what can be other reason. You need check carefully for first your connection system, then connect-disconnect sequence, check that and then only connect other after success disconnection. Sry not look still to your code, maybe other gives you other/better hint. I'll be logically step by step check system (connections, IPs, Ports,...).

 I have changed ID for second connection, and used the "connected" flag for the sequence instead of a fixed time, and now it works...really thank you so much! Also to everyone that have reply me;

Duris_I

Hello,

look, this is only improvement to your code in case of this error occured. In case of 80A3 it can be also f.ex. re-establsih existing connection or already mentioned attempt to terminate not existing connection. Other (first general problem) can be using of same connection ID with parameters for both blocks, now I'm only think what can be other reason. You need check carefully for first your connection system, then connect-disconnect sequence, check that and then only connect other after success disconnection. Sry not look still to your code, maybe other gives you other/better hint. I'll be logically step by step check system (connections, IPs, Ports,...).