PMAC Product Guide Home Switches While normally closed-to-ground switches are required for the overtravel limits inputs, the home switches can be either normally closed or normally open types. The polarity is determined by the home sequence setup, through the I-Variables I902, I907, ... I977. However, for the following reasons, the same type of switches used for overtravel limits are recommended: • Normally closed switches are proven to have greater electrical noise rejection than normally open types. • Using the same type of switches for every input flag simplifies maintenance stock and replacements.
Motor Signals Connections Incremental Encoder Connection The JMACH connector provides two +5V outputs and two logic grounds for powering encoders and other devices. The +5V outputs are on pins 1 and 2; the grounds are on pins 3 and 4. The encoder signal pins are grouped by number: all those numbered 1 (CHA1, CHA1/, CHB1, CHC1, etc.) belong to encoder #1. The encoder number does not have to match the motor number, but usually does. If the PMAC is not plugged into a bus and drawing its +5V and GND from the bus, use these pins to bring in +5V and GND from the power supply. Connect the A and B (quadrature) encoder channels to the appropriate terminal block pins.
For encoder 1, the CHA1 is pin 25, CHB1 is pin 21. If there is a single-ended signal, leave the complementary signal pins floating -- do not ground them. However, if single-ended encoders are used, make sure that the corresponding jumpers E24 to E27 are set on position 1-2. For a differential encoder, connect the complementary signal lines -- CHA1/ is pin 27, and CHB1/ is pin 23. The third channel (index pulse) is optional; for encoder 1, CHC1 is pin 17, and CHC1/ is pin 19. Example: differential quadrature encoder connected to channel #1: Note: The Encoders screen of the EZ-PMAC Setup Software checks the proper direction and functioning of any encoder input in PMAC. Machine Connections 29