I have a controller T3-TB reading the open collector output below. We originally thought it was 0-10v but that doesn’t appear to be the case. Please let me know if this is something that can be read and how if possible. We are trying to read motor speed. Thanks, Bryan
I’d put the input range to ON/OFF and signal type to Thermistor/Dry Contact. This will engage a weak pullup resistor tied high with 3V on board the T3 controller. It will be in parallel with the 10V pullup on board your motor control board which will overwhelm the weak 3V pullup and should work. Put a volt meter on GND and A1 and you should see a 10V pulse there, then tie in the T3 input to GND and A1 and hopefully the pulses will register on the T3.
Let me know how you make out, we can set up a test here on Monday if need be.
I’m not having any luck with this. I tried On/Off and it will go on for a while then off for a while with no attention to the speed of the motor. I tried frequency and not getting any better luck. The fans are actually running the same speed in the attached example.
Spring will set up a test today, stand by for news shortly.
After reading a bit about pull up resistors I believe I will need one. Can you diagram how I can get the 10V from the controller and attache A1?
The 10V has no on board pull up it reads a steady 11.2V The A1 OC out reads a slow 0.2V pulse. what are the voltages needed by the logic gate to read frequency? Ground is already tied to controoler ground bus through the 0-10V output to fan.
Okay, so the TB controller doesn’t have a fast count feature at the moment. I am giving a fan status signal by putting the input to thermister/dry contact and using a 6.2K ohm resistor in place of the 5K. This was arrived at by finding the mid-point of resistance required to get on/off reading on the input. It’s fairly critical as the pulse voltage doesn’t change much. Signal pulses at a quick rate and I time it to find out if the 0-10v fan speed control signal is lost, pulse in steady on state or if the power was lost, pulse in steady off state. If not pulsing I turn the variable to off. It takes a couple of scans to turn the state off/on but will give a reliable indication of fan status.
10 REM INDICATE OAF STATE
20 IF TIME-ON ( OAFFB_V ) < 00:00:01 THEN START OAOFFON
30 IF TIME-ON ( OAFFB_V ) > 00:00:10 THEN STOP OAOFFON
40 IF TIME-OFF ( OAFFB_V ) > 00:00:10 THEN STOP OAOFFON