PMAC Quick Reference Guide PMAC Connectors and Indicators Display Port Outputs (JDISP Port) The JDISP connector (J1) connects the PMAC to the Acc-12 or Acc-12A liquid crystal displays, or of the Acc-12C vacuum fluorescent display. Both text and variable values may be shown on these displays through the use of the DISPLAY command, executing in either motion or PLC programs. Control-Panel Port I/O (JPAN Port) The JPAN connector (J2 on PMAC PC, Lite, VME, and top board of PMAC STD) is a 26-pin connector with dedicated control inputs, dedicated indicator outputs, a quadrature encoder input, and an analog input. The control inputs are low true with internal pull-up resistors.
They have predefined functions unless the Control Panel Disable I-Variable (I2) has been set to 1. If this is the case, they may be used as general-purpose inputs by assigning an M-Variable to their corresponding memory-map locations (bits of Y address $FFC0). Thumbwheel Multiplexer Port I/O (JTHW Port) The Thumbwheel Multiplexer Port, or Multiplexer Port, on the JTHW (J3) connector has eight input lines and eight output lines. The output lines can be used to multiplex large numbers of inputs and outputs on the port, and Delta Tau provides accessory boards and software structures (special M-Variable definitions) to capitalize on this feature.
Up to 32 of the multiplexed I/O boards may be daisy-chained on the port, in any combination. Serial Port Connection For serial communications, use a serial cable to connect the PC’s COM port to PMAC’s serial port connector (J4 on PMAC PC, Lite, and VME; J1 on PMAC STD’s bottom board). Delta Tau provides cables for this purpose: Acc-3D connects PMAC PC or VME to a DB-25 connector; Acc-3L connects PMAC Lite to a DB-9 connector; and Acc-3S connects PMAC STD to a DB-25 connector. Standard DB- 9-to-DB-25 or DB-25-to-DB-9 adapters may be needed for a particular setup.
General-Purpose Digital Inputs and Outputs (JOPTO Port) PMAC’s JOPTO connector (J5 on PMAC PC, Lite, and VME) provides eight general-purpose digital inputs and eight general-purpose digital outputs. Each input and each output has its own corresponding ground pin in the opposite row. The 34-pin connector was designed for easy interface to OPTO-22 or equivalent optically isolated I/O modules. Delta Tau’s Acc-21F is a six-foot cable for this purpose. The PMAC STD has a different form of this connector from the other versions of PMAC. Its JOPT connector (J4 on the base board) has 24 I/O, individually selectable in software as inputs or outputs.
Machine Connectors The primary machine interface connector is JMACH1 (J8 on PMAC PC, J11 on PMAC Lite, P2 on PMAC VME, J4 on PMAC STD top board). It contains the pins for four channels of machine I/O: analog outputs, incremental encoder inputs, and associated input and output flags, plus power-supply connections. The next machine interface connector is JMACH2 (J7 on PMAC PC, P2A on PMAC VME, J4 on the middle board of an 8-channel PMAC STD, not available on a PMAC Lite). Essentially it is identical to the JMACH1 connector for one to four more axes. It is present only if the PMAC card has been fully populated to handle eight axes (Option 1), because it interfaces the optional extra components.
LED Indicators PMACs with the Option CPU have three LED indicators: red, yellow, and green. The red and green LEDs have the same meaning as with the standard CPU: when the green LED is lit, this indicates that power is applied to the +5V input; when the red LED is lit, this indicates that the watchdog timer has tripped and shut down the PMAC. Introduction 5