Given
- USB-6361 mass-termination DAQ (spec sheet)
- SC-2345 carrier (manual)
- 2 counter inputs: 2 X4 rotary encoders
- 2 counter outputs: 2 PWM signals that modulate power from benchtop power supply to electromagnets
I've connected 1 encoder and 2 PWM signals to my DAQ via the carrier's terminal block (see diagram on page 28 of carrier PDF).
The encoder requires A, B, Z, 5V, and GND terminals, while each PWM output requires a "signal" line and GND.
- encoder 1:
Device A - sc terminal A37/PFI 8 - DAQ PFI 8/ CTR0 A
Device B - sc terminal C45/PFI 10 - DAQ PFI 10/CTR0 B
Device Z - sc terminal C3/PFI 9 - DAQ PFI 9/CTR0 Z - PWM 1
signal - sc terminal C40/PFI 13 - DAQ PFI 13/CTR1 OUT - PWM 2
signal - sc terminal A1/PFI 14 - DAQ PFI 13/CTR2 OUT
Power and ground are connected to the single power and multiple ground terminals in the carrier.
Problem
I need to connect another rotary encoder. I tried shifting my setup to the following configuration:
encoder 1 = CTR 0, encoder 2 = CTR 1, PWM 1 = CTR 2, PWM 2 = CTR 3
- encoder 1:
Device A - sc terminal A37/PFI 8 - DAQ PFI 8/ CTR0 A
Device B - sc terminal C45/PFI 10 - DAQ PFI 10/CTR0 B
Device Z - sc terminal C3/PFI 9 - DAQ PFI 9/CTR0 Z - econder 2:
Device A - sc terminal C42/PFI 3 - DAQ PFI 3/ CTR1 A
Device B - sc terminal C46/PFI 11 - DAQ PFI 11/CTR1 B
Device Z - sc terminal C41/PFI 4 - DAQ PFI 4/CTR1 Z - PWM 1
signal - sc terminal A1/PFI 14 - DAQ PFI 14/CTR2 OUT - PWM 2
signal - sc terminal ???/PFI 15 - DAQ PFI 15/CTR3 OUT
But the carrier's terminal block doesn't have any additional counter I/O terminals. What can I do?
- Is there any easy way to reconfigure one of the unused carrier terminals into PFI 15/CTR 3 OUT?
- Should I use one of the carrier's analog or digital I/O for counter I/O?
A cursory internet search reveals that this is possible and discouraged for PWM control of power supplies (which is what I'm doing), so I'd use this for encoder input. - If I have to resort to modifying analog or digital I/O for counter I/O, what would you recommend--analog or digital?
I'm thinking I'd use a software-timed digital input. Is this correct?
I'd appreciate any and all insight!
-Farid
Attached: picture of all instrument pin-outs