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Showing results for tags 'rs485'.
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I just plugged in this board and to test it out. My intent is to use it in a RS422 format, but will need to understand what changes I need to make later. I've opened up the arduino sketch and uploaded it to my AST-CAN485 from Sparkfun. I modified Digilent's the code so it uses the alternative software serial library. Other than that, it's all the same. When I run the code and open up the serial monitor, the loopback is actually happening in the hardware. I can unplug the looped wires and still get a message back. So the echo example code seems to not work properly. Any aid in understanding this would be great. PmodRS485-MPIDE-demo1.ino
I am trying to use a Pmod485 (P/N 410-310) to connect an Arduino (TTL) to a motor controller (RS485). I am only using 1 Pmod485 and I am assuming I do need to short JP1, is this done just by sliding the blue cap over both pin headers? Also, the IC block diagram shows 2 separate GND (GND1 and GND2) but the module only has 1 GND available on the pin header. Does this mean both GND on the IC are connected together? pmod_pmod_pmodrs485_rm.pdf
I need to do oscilloscope testing on BAS networks talking over RS485. Protocols like modus, BacNet, Johnson N2, and others. I need to know if your product line includes anything that can help with this. The pertinent specs for my use I suppose is: Voltage: +-5vdc all the time, with 24vac (typically 22v to 29vac in practice) on occasion if possible. Comm speed: 9600 bps, up to 115200 bps. I see 78600 and 38400 most frequently. I will be most commonly be using an oscilloscope measuring differential between the + and - on the comm trunk, occasionally between + and a reference, and - and the same reference. The reference is usually the common leg of a 24vac transformer, but it can also be ground or a provided, dedicated reference wire. I need to use an Oscilloscope to find ground loops causing a voltage offset, noise from a VFD or lighting ballast, lack of termination, or improper voltage biasing, capacitance in the wire preventing the voltage from reaching the amplitude necessary to trigger a 0 or 1 value, shorts in the cable from rubbing or cutting that has voltage draining from a conductor to shield or between conductors. So first off, is the Analog Discovery 2 able to provide useful data? Is its oscilloscope able to provide readings on this type of network with good enough resolution that I can see the issues I am looking for? Secondly, what is the best way to hook it up? I was looking at the BNC connector board, as it provides the typical Oscilloscope probe connections. But then I noticed that it changes differential terminals into Single Ended ones and wondered if you may not have something better. For example, can I pull Oscilloscope readings from the Pmod RS485? https://reference.digilentinc.com/reference/pmod/pmodrs485/start#example_projects Or the Pmod-ad5? https://store.digilentinc.com/pmod-ad5-4-channel-4-8-khz-24-bit-a-d-converter/ My life is sitting on a bucket in a basement programming Air handlers and mechanicals... so the likelihood of shorting out this Analog Discovery 2 by touching a Single End ground clip to the wrong thing is plausible, and shorting out my controller's RS485 transceivers is likely. Crap happens in mechanical rooms. I would much rather use differential connections. If I could add the to Analog Discovery 2 to the trunk using the Pmod-RS485 and scope it - that would be beyond perfect.