Hi,
We've been doing a lot of work to get our DH+ networks back as they should be, following years of poorly executed modifications.
We've been using Netdecoder, and Picoscope PC based oscilloscopes as part of this process.
I've read a lot of documentation about fault finding DH+, and how it works. I've found some good info on this forum, as well as on the Rockwell Knowledgebase. It's all been very useful.
Perhaps I'm going too far with this now - border line obsessed, but I want to decode the oscilloscope trace. What I cant understand is why it doesn't resemble the Netdecoder packets.
I've added an attachment with the first trend out of the scope on power up of the PLC (the PLC is just sat on my desk, and not connected to a network). also, the first packet logged in net decoder (taken at the same time as the scope) is shown.
There's no similarity at all... Even if you think there might be some preamble bytes. I'd have thought the net decoder software would just be picking up the same signal as the scope.
Has anyone else done anything like this with more success? I was kind of expecting to change the binary to ASCII and then start seeing some DLE/STX.....DLE/ETX etc.
Or is this somehow recoded in the U2DHP box and I'm wasting my time?!
Thanks for any help...
Andy
We've been doing a lot of work to get our DH+ networks back as they should be, following years of poorly executed modifications.
We've been using Netdecoder, and Picoscope PC based oscilloscopes as part of this process.
I've read a lot of documentation about fault finding DH+, and how it works. I've found some good info on this forum, as well as on the Rockwell Knowledgebase. It's all been very useful.
Perhaps I'm going too far with this now - border line obsessed, but I want to decode the oscilloscope trace. What I cant understand is why it doesn't resemble the Netdecoder packets.
I've added an attachment with the first trend out of the scope on power up of the PLC (the PLC is just sat on my desk, and not connected to a network). also, the first packet logged in net decoder (taken at the same time as the scope) is shown.
There's no similarity at all... Even if you think there might be some preamble bytes. I'd have thought the net decoder software would just be picking up the same signal as the scope.
Has anyone else done anything like this with more success? I was kind of expecting to change the binary to ASCII and then start seeing some DLE/STX.....DLE/ETX etc.
Or is this somehow recoded in the U2DHP box and I'm wasting my time?!
Thanks for any help...
Andy