The following table lists the default input terminals for various counter measurements on M Series devices, including M Series USB devices, such as the NI USB 6259 screw terminal and NI USB-6229 BNC devices. You can use a different PFI line for any of the input terminals. To change the PFI input for a measurement, use the NI-DAQmx channel attributes/properties.

Measurement Ctr0 Ctr1
Count Edges
  • Edges: PFI 8
  • Count Direction: PFI 10
  • Edges: PFI 3
  • Count Direction: PFI 11
Pulse Width Measurement PFI 9 PFI 4
Period/Frequency Measurement (Low Frequency with One Counter) PFI 9 PFI 4
Period/Frequency Measurement (High Frequency with Two Counters) PFI 8 PFI 3
Period/Frequency Measurement (Large Range with Two Counters) PFI 8 PFI 3
Semiperiod Measurement PFI 9 PFI 4
Two-Edge Separation Measurement
  • Start: PFI 10
  • Stop: PFI 9
  • Start: PFI 11
  • Stop: PFI 4
Position Measurement
  • A: PFI 8
  • B: PFI 10
  • Z: PFI 9
  • A: PFI 3
  • B: PFI 11
  • Z: PFI 4

The following table lists the output terminals for counter output. You can use a different PFI line for any of the output terminals.

Ctr0 Ctr1
PFI 12 PFI 13

Some M Series devices, including the NI 6010, NI 6154, NI 6221 (37-pin), and NI 623x, use the 37-pin DSUB connector. These devices have different counter terminal defaults. Refer to the 37-Pin DSUB Signal Connections for Counters for the default input terminals on these devices. Bus-powered M Series devices, such as the NI USB-621x devices, also have different counter terminal defaults. Refer to the Bus-Powered M Series Signal Connections for Counters for the default input terminals on these devices.