PMAC Quick Reference Guide TROUBLESHOOTING PMAC is a highly reliable device and has several safety mechanisms to prevent continuous damage and malfunctions. When PMAC shuts down or an erratic behavior is observed, the following reset procedure should be used. Resetting PMAC to Factory Defaults 1. If PMAC is communicating with the host computer, skip steps 2-7 on this list. 2. Turn off PMAC or the host computer where PMAC is installed. 3. Remove all cables connected to PMAC leaving connected only the serial port and power cables if present. 4.
Using the appropriate hardware reference for the particular PMAC in question, check that all its jumpers are at the default configuration or changed properly to accommodate the particular setup for the machine. Make sure that jumper E50 is properly installed; otherwise any SAVE command issued to PMAC will not have any effect. 5. Place the jumper E51 in PMAC (1) or jumper E3 on PMAC2. This is a hardware re-initialization jumper. 6. After power-up, try establishing communications again with a reliable software package like the PEWIN program provided by Delta Tau. 7. On power-up, with the re-initialization jumper installed, some PMACs with the flash memory option will be in bootstrap mode.
This means that PMAC will accept a binary file downloaded to change its internal firmware. If this is the case, follow the instructions on the PEWIN screen to disable the downloading process (usually pressing CTRL+R ). 8. Try communications with PEWIN and type the following commands when the terminal is opened successfully (follow the communications troubleshooting section below in case communications are still not established): $$$*** ;Global Reset P0..1023=0 ;Reset P-variables values Q0..1023=0 ;Reset Q-variables values M0..1023->* M0..1023=0 ;Reset M-variables definitions and values UNDEFINE ALL ;Undefine Coordinate Systems SAVE ;Save this initial, clean configuration 9.
If the re-initialization jumper was installed, remove it at this time. Restore PMAC in the computer and power it up. 10. Try communications again and configure PMAC for the application. Make sure there is a backup file saved in the host computer with all the parameters and programs that PMAC needs to run the application. Furthermore, since the host computer could also fail and be replaced, save the configuration file both in the host computer and in a floppy disk stored in a safe place. This file must be downloaded and a SAVE command must be issued to PMAC.
The Watchdog Timer (Red LED) The PMAC motion control board has an on-board watchdog timer (sometimes called a dead-man timer or a get-lost timer) circuit whose job it is to detect a number of conditions that could result in dangerous malfunction, and shut down the card to prevent a malfunction. The philosophy behind the use of this circuit is that it is safer to have the system not operate at all than to have it operate improperly. Because the watchdog timer wants to fail and many components of the board, both hardware and software, must be working properly to keep it from failing, it may not be immediately obvious what the cause of a watchdog timer failure is. Troubleshooting 67