Hello there :)
As I am really new to this topic, I hope I can get some help here ;)
What I am looking for, is a RS422 Receiver with two differential line pairs, which returns a 3,3 V TTL signal for my raspberry pi (correct me if I am wrong, but that is what I think I need to do the following).
The plan is to connect this sensor (linear encoder) to my raspberry pi:
- Siko MSK2000
https://www.siko-global.com/adbimage/1712/asset_original/data-sheet-msk2000.pdf - Operating voltage: 5 V
- Output signal low / high : RS422 specific (as far, as I understood, it only uses the defined voltage levels of RS422 and not a full RS422 communication)
- Output signals: A, /A, B, /B (inverted version)
- Resolution: 0,25 mm
The sensor works with RS422 voltage levels. RS422 uses differential broadcast, so I need an IC, which gives me the corresponding TTL levels for my raspberry pi, which uses 3,3 V.
I found this IC:
http://www.ti.com/product/AM26LV32E-EP/technicaldocuments
As far as I can tell, this IC fits my needs. It works with 3,3 V (so I guess it returns a 3,3 V TTL signal?) and accepts 5 V input signals (RS422). BUT this one is a quad differential line receiver, so it has four differential line pairs. I only need two.
Can I just use two of them, or should I get better use another IC? I could not find a similar one, so could you maybe help me with this?
Another question: What data rate do I need for an encoder? Is there a way to calculate that with the given specs in the data sheet?
Found an answer for that: f = 25 m/s * 4000 pulses / m = 100.000 pulses / s -> 250 kbps should be enough for that.
Thanks a lot.
Kind regads,
Niko
