dodge_neon

OK, got it. I tested this setup and determined it works--now to update some diagrams. While I have you on this topic, a last question: I have a similar issue on that previous project I mentioned. We want to switch that rig from USB-201s to USB-231s. Can I configure a relay setup with the USB-231 the same way as this USB-2408, or does the 2408's open collector enable that specifically? Thank you!

Thanks, JRys, this is helpful. Understood. My setup uses 6X 5V-35mA relays, so I'll be sure our software won't try to drive more than four at once. I got used to the USB-200 series on a previous project, where we were able to drive the same relays directly with the DOUTs. I think I'm understanding I need to treat these more like a transistor than a simple output driver. OK, I believe that should look like this, with our 5V relays. I have an external 5V supply I'll be using--since there isn't measurement being done on the DIO circuits, it should be fine to gang my 12V, 5V, DGND, and Chassis ground all together? fig 4

Hello, I am using an MCC USB-2408-2AO to drive an end-of-line testing device for a 12V pneumatics control manifold. This DAQ was selected because it can output 150mA on each DIO, which we'll be using to operate some 5V/35mA relays. The 16 AI channels are also being used to measure some voltage inputs. We will be running a custom python software to operate the device when our project is done, but for now I'd like to configure it for quick DASYlab control. I have run into an issue with the DIO circuits pull up/pull down feature, I believe. DIO_0 and DIO_1 should be inputs, 0-5V TTL, wired to NO switches. DIO_2-DIO_7 should be outputs, 0-5V to drive relays directly. I have a DASYlab sheet configured like so: fig 1 With this setup and the DAQ factory configured, I found all of the DIO circuits reading HI. This was regardless of output from DASYlab, or input from a hardware switch. I read into the manual to determine I would need to switch the pull-up/pull-down jumper: fig 2 Switching my DAQ jumper to 2-3 did make DIO_0 and DIO_1 read the hardware TTL correctly, but my other six DOUTs are not going HI when I switch them in DASYlab. I switched the jumper back to 1-2, and now my DIO_0 and DIO_1 are stuck HI, but I can read at least some effect on the DOUTS. fig 3 To be specific: J6 pos 1-2 with RELAYS>0 LO (fig 1), DIO_2 (node 25, fig 3) reads V = 5.00 HI with RELAYS>0 HI, DIO_2 reads V = 0.00 LO with a relay connected, the 5.00V HI becomes 0.495V. Switching the J6 jumper: J6 pos 2-3 with RELAYS>0 LO, DIO_2 reads V = .008 with RELAYS>0 HI, DIO_2 reads V= 0.00 with a relay connected, the .008 becomes .007. I'm guessing I have something configured incorrectly. Can anyone advise?

HELLO I am a ludicrously undersupervised technician at a pneumatics startup located in Michigan. I use MCC products for custom test equipment on a shoestring, mostly. I am looking forward to learning what can be done better in my lab!