Can I Use the SCC-CTR01 Module With Quadrature Encoders and Up/Down Event Counting?

Hardware: SCC>>Modules>>SCC-CTR01

Problem: I have an SCC-CTR01 isolated counter module. What are the limitations of using this module with M Series and E Series devices?

Solution:
For event counting applications, the signal to be counted should be applied to the isolated source input of the module. For event counting applications where the use of external Up/Down control lines are needed, these caveats exist:

For E Series devices, the Up/Down lines for CTR0 and CTR1 are digital lines P0.6 and P0.7, respectively. These lines correspond to pins 16 and 48 and are available as non-isolated inputs in the SC-2345 breakout area. Isolated inputs for these signals are NOT supported directly by the SCC-CTR01 module. If your application requires isolated inputs for these signals, an SCC-DI01 isolated input module can be used to access the indicated digital lines.
For M Series devices the Up/Down lines for CTR0 and CTR1 are CTR 0 Aux and CTR 1 Aux, respectively. These lines are also exposed in the SC-2345 breakout area as non-isolated pins 45 and 40, but for isolated inputs of these signals the counter gate pins can be used for Up/Down control. This setting can be made using a DAQmx Channel Property node as shown here:

For quadrature encoder applications with M Series devices that support Z-indexing, the CTR Aux pins in the SC-2345 breakout area must be used. Isolated inputs for these signals are not available. This is necessary because both the source and gate inputs of the counter are needed to connect the two quadrature encoder phase signals.

Related Links:
NI SCC-DI01 1-channel Optically Isolated Digital Input Module

Attachments:

Report Date: 09/20/2005
Last Updated: 10/05/2005
Document ID: 3PJGJ2RM

Your Feedback!

Poor | Excellent

Yes

Document Quality?

Answered Your Question?

Please Contact NI for all product and support inquiries.