Added comment about using gpct_encoder demo with 660x boards.

diff --git a/demo/gpct_encoder.c b/demo/gpct_encoder.c
index f535424687738b883a4602b262e84cc4e87bb490..d36f9f366bbc45eab7019cedd99055f129b251e0 100644 (file)
--- a/demo/gpct_encoder.c
+++ b/demo/gpct_encoder.c
@@ -45,6 +45,8 @@ int ni_gpct_start_encoder(comedi_t *device, unsigned subdevice,
 
        comedi_set_gate_source(device, subdevice, 0, 0, NI_GPCT_DISABLED_GATE_SELECT);
        comedi_set_gate_source(device, subdevice, 0, 1, NI_GPCT_DISABLED_GATE_SELECT);
+       /* note, the comedi_set_other_source calls will fail on 660x boards, since they
+        * don't support user selection of the inputs used for the A/B/Z signals. */
        comedi_set_other_source(device, subdevice, 0, NI_GPCT_SOURCE_ENCODER_A, a);
        comedi_set_other_source(device, subdevice, 0, NI_GPCT_SOURCE_ENCODER_B, b);
        comedi_set_other_source(device, subdevice, 0, NI_GPCT_SOURCE_ENCODER_Z, z);