Exported variables not working
I have a problem with Freelance 2016.
I'm not getting a correct reading of a variable(s) when I use it on another Resource.
I already set the variable(s) to be able to be exported by setting "Y" on the X column on the variable list.
I have no problem doing a plausibility check or even downloading to the PLC. However, the programming is not responing. When I enter Comissioning Mode and place the cursor over the variable, I can see its current state or value, but when I place the cursor on the connecting line to the right of it, I get a reading of FALSE for boolean variables and 0.0 for real variables.
What could be causing this issue. None of the variables are double-written either.
I'm using Freelance 2016 with an AC902F CPU.
Thanks a lot for your help!
Value exchange between controlers works with UDP broadcast datapackets.
The station who hosts the variable sends the values with the LatSnd task.
The other stations reciving all values, and there LatRcv task extract all values of interest.
If there is no value packet is recived between LatRcv runs, the station will rise a "Timeout from station" message.
To solve your problem, you can check:
- Does the LatSnd task run? Does the first station send UDP packets?
- Do this packets arive the other stations? Or maybe eaten by firewalls between the stations?
- Does the LatRcv task run? Does the station have a "Timeout from station" message?
- Is the netmask setting of the stations correct? Broadcast packets wo are not fit the netmask will be ignored by the stations!
There is a variable called <Name of receiving resource>.<Name of sending resource>.RecvErr that indicates potential errors on the receiving side.
There is a variable called <Name of sending resource>.SendErr too.
Are the LatSnd task on the sender and the LatRcv task on the receiver running? Do they show the right variables in the parameter mask?
is your problem solved?
If I remember correctly, if you put the cursor in commissioning mode over the variable, the engineering Software will read the value from the source station directly (the exporting station) if you put the cursor on the line, it will read the data from the local station. Thus your observation shows that the variable is generated with the correct values in the exporting station, but for some reason not received in the importing station.
There used to be an issue with latcom changes in incremental configurations but I remember it for older Freelance versions only. Nevertheless do a donwload whole Station to both controllers if possible. Also check that the controllers are in the same subnet and that the subnet masks fit.