PicoScope 7 Software
Available on Windows, Mac and Linux
Scope for Industrial Communications
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Michael_Sovereign
- User
- Posts: 2
- Joined: Fri Mar 26, 2021 1:13 pm
Scope for Industrial Communications
Hello,
I am considering buying a scope for work, I do not think my employer will cover this, so cost is a consideration.
I am new to oscilloscopes and have an opportunity to learn how to troubleshoot and analyze different circuits.
Essentially, I want to use this on different industrial communication protocols such as:
Modbus TCP/IP and RTU including RS-485 and RS-232
Profibus
HART
EtherCAT (nice to have)
Additionally, it would be nice to test 600VAC VFDs
Questions:
1) Are two channels sufficient? What situation would I use 4?
2) Should I get MSO and what would its purpose be in the above protocols?
3) What do I need to test Ethernet?
4) What is a comfortable amount of memory/bandwidth/sampling for the above protocols?
are the 2000 series capable enough, or will I wish I went with the 3000 series? I was considering the 3204D or 3404D with or without MSO.
Thank you,
Michael
I am considering buying a scope for work, I do not think my employer will cover this, so cost is a consideration.
I am new to oscilloscopes and have an opportunity to learn how to troubleshoot and analyze different circuits.
Essentially, I want to use this on different industrial communication protocols such as:
Modbus TCP/IP and RTU including RS-485 and RS-232
Profibus
HART
EtherCAT (nice to have)
Additionally, it would be nice to test 600VAC VFDs
Questions:
1) Are two channels sufficient? What situation would I use 4?
2) Should I get MSO and what would its purpose be in the above protocols?
3) What do I need to test Ethernet?
4) What is a comfortable amount of memory/bandwidth/sampling for the above protocols?
are the 2000 series capable enough, or will I wish I went with the 3000 series? I was considering the 3204D or 3404D with or without MSO.
Thank you,
Michael
Re: Scope for Industrial Communications
For all ethernet base protocols you will be better of with wireshark.
For 485 and 422 based protocols the best you need or a differential probe or use 2 ch per data stream and a math A-B function to see the clean signal.
On your desk you can do with 1 channel per data stream (RX/TX) but in industrial situations you will need the differential signal to trouble shoot.
differential probes are expensive (unless you buy a 4444 that has 4 differential inputs)
I would use a 4 channel scope so you can use a digital output on the PLC or other controller to trigger the scope and capture the bus on the trigger moment.
If I have time and don't forget it I will post some captures of polluted signals where the differential signal is ok.
Benno
For 485 and 422 based protocols the best you need or a differential probe or use 2 ch per data stream and a math A-B function to see the clean signal.
On your desk you can do with 1 channel per data stream (RX/TX) but in industrial situations you will need the differential signal to trouble shoot.
differential probes are expensive (unless you buy a 4444 that has 4 differential inputs)
I would use a 4 channel scope so you can use a digital output on the PLC or other controller to trigger the scope and capture the bus on the trigger moment.
If I have time and don't forget it I will post some captures of polluted signals where the differential signal is ok.
Benno
Re: Scope for Industrial Communications
As promised a CAN signal with heavy inverter polution
See also below image.
You can try for yourself to decode the CAN data on channel A or Channel C
Decoding is here done on the math channel A-C
Benno
See also below image.
- 2022-04-29_07-25-26.png (10.3 KiB) Viewed 2522 times
Decoding is here done on the math channel A-C
Benno
- Attachments
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- 20220429-0001.psdata
- (2.31 MiB) Downloaded 260 times
Re: Scope for Industrial Communications
An other example why differential probes only tell half the story.
Black would be the only signal you see with a differential probe, the blue and green gives the individual signals compared to ground on the bus, and the black is calculated from A-C
Benno
Black would be the only signal you see with a differential probe, the blue and green gives the individual signals compared to ground on the bus, and the black is calculated from A-C
Benno
- Attachments
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- 2022-04-29_07-43-58.png (11.09 KiB) Viewed 2521 times
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- 20220429-0002.psdata
- (2.38 MiB) Downloaded 257 times