Hello
There is a bug which prevent to write more than 12 Boolean variables at the same time.
This issue is strictly related to the one I opened a while ago for the node-red-contrib-s7 package (st-one-io/node-red-contrib-s7#90)
Steps to reproduce:
Write more than 12 Boolean variables at the same time using the writeItems method of the S7ItemGroup class. This raises a request timeout.
Problem:
After investigating, the problem seems related to the way the reqItemLength variable is computed.
A writing_var (s7) request for multiple Boolean variables requires the following bytes:
- HEADER: 10 bytes
- PARAMETERS: 2 bytes + 12 bytes per variable
- DATA: 4 bytes per variable + 1 byte per variable + 1 extra fill byte per variable (something like a separator character)
The reqItemLength does not take into account the fill byte.
I'm going to open a pull request to fix it.
Filippo
Hello
There is a bug which prevent to write more than 12 Boolean variables at the same time.
This issue is strictly related to the one I opened a while ago for the node-red-contrib-s7 package (st-one-io/node-red-contrib-s7#90)
Steps to reproduce:
Write more than 12 Boolean variables at the same time using the writeItems method of the S7ItemGroup class. This raises a request timeout.
Problem:
After investigating, the problem seems related to the way the reqItemLength variable is computed.
A writing_var (s7) request for multiple Boolean variables requires the following bytes:
The reqItemLength does not take into account the fill byte.
I'm going to open a pull request to fix it.
Filippo