| Products > Test Equipment |
| DIY scan card for Keysight 34970A |
| (1/13) > >> |
| voltsandjolts:
I've cobbled together a scan card to fit in the 34970A card slot. It's basically a re-hash of my Keithley 20 channel card. I haven't written the firmware yet and first job is to decode the uart serial protocol, which runs at 187500 baud 9N1. I've searched but can't see any info out there about the command structure. Does anybody have any info on this? ...if not I'll dig out the logic analyser, but thought I'd ask first. Edit 19JUN2022: I have attached here the schematic pdf, gerbers, firmware source and altium files. This card seems functional to me but has not been extensively tested, there may be gremlins ^-^ SAFETY NOTICE: Your choice of SSR bus relays must withstand the maximum voltage placed on the bus by any card in the DAQ. Perhaps armature relays would be a better choice for the bus relays. You must not exceed manufacturer ratings for the DAQ voltage capabilities (300V IIRC?). This design is openly published in the hope that it is useful for development of your own card(s). This design is not extensively tested and comes with no warranty, express or implied. Edit 27JUL2022: Firmware updated to include relay cycle counters to demonstrate the DAQ commands. They are just in RAM, so start at 0 on every power-up. |
| Kean:
I don't have any info, but I do have 2 x 34970A and 1 x 34972A, plus 2 each of 34901A/903A/907A. So I'd be happy to assist with verifying any protocol info. One of my 34970As I bought cheaply second hand. It needs some cleanup and a replacement fan, so I'm happy to do "guinea pig" testing with it. |
| strawberry:
dont know if DS75S temp sensor is crucial part for temperature measurement |
| H.O:
Same here, no info on the protocol but very interested. I have 2 1/2 34970 and a couple of different modules. Let me know if there's anything I can do to help. |
| voltsandjolts:
Thanks for the offers of help. --- Quote from: strawberry on May 11, 2022, 07:08:23 pm ---dont know if DS75S temp sensor is crucial part for temperature measurement --- End quote --- I'm focused on voltage measurements, don't need thermocouple scanning, but if I get this card running, you could easily adapt it to add a cold junction temperature measurement. The pyhysical cold junction on the 34901A is not that impressive, just a couple of copper planes, but I suppose its adequate given the plastic enclosure/stable conditions in the meter. The Keithley 2001-TSCAN is better with it's copper block. |
| Navigation |
| Message Index |
| Next page |