User`s manual
Installing and Configuring PMAC
Page - 20
3.3 - Establishing Host Communications
Either the Executive or Setup program can be used to establish initial communications with the card. Both programs have
menus that allow you to tell the PC where to expect to find the PMAC and how to communicate with it at that location. If
you tell it to look for PMAC on the bus, you must also tell it PMAC's base address on the bus (this was set up with jumpers
on PMAC). If you tell it to look for PMAC on a COM port, you must tell it the baud rate (this was set up with jumpers or
switches on the PMAC). Once you have told the program where and how to communicate with PMAC, it will attempt to
find PMAC at that address by sending a query command and waiting for the response. If it gets the expected type of
response, it will report that it has found PMAC, and you will be able to proceed. If it does not get the expected type of
response after several attempts, it will report that it has not found PMAC.
3.3.1 - Terminal Mode Communications
Once the program reports that it has found PMAC the program should be in terminal emulation mode, so that the PC is
acting as a dumb terminal to PMAC. Check to see if you get a response by typing I10<CR> (<CR> means carriage return,
the ENTER or RETURN key). PMAC should respond with a six or seven digit number. If you are not getting the expected
results, check the following:
1) Is the green LED (power indicator) on PMAC's CPU board ON, as it should be? If it is not, find out why PMAC is not
getting a +5V voltage supply.
2) Is the red LED (watchdog timer indicator) on PMAC's CPU board OFF, as it should be? If it is ON, make sure PMAC
is getting very close to 5V supply -- at less than 4.75V, the watchdog timer will trip, shutting down the card. The
voltage can be probed at pins 1 and 3 of the J8 connector (A1 and A2 on the PMAC-VME). If the voltage is
satisfactory, follow these steps:
- Turn-off PMAC or the Host computer where it is plugged into.
- Place the Jumper E51 (the hardware re-initialization jumper) and turn PMAC back on.
- If PMAC is in bootstrap mode, send a <CONTROL-R> character to PMAC to bypass the firmware download.
- If communications are successful type “$$$***” and “SAVE” in the terminal window.
- Turn-off PMAC, remove the jumper E51 and try communications again.
Bus Communications
3) Do the bus address jumpers (E91-E92, E66-E71) set an address that matches the bus address that the Executive
program is trying to communicate with?
4) Is there something else on the bus at the same address? Try changing the bus address to see if communications can be
established at a new address. Address 768 (300 hex) is usually open.
Serial communications
5) Are you using the proper port on the PC? Make sure if the Executive program is addressing the COM1 port, which
you have cabled out of the COM1 connector.
6) Does the baud rate specified in the Executive program match the baud rate setting of the E44-E47 jumpers on PMAC?
7) With a breakout box or oscilloscope, make sure you see action on the transmit lines from the PC as you type into the
Executive program. If you do not, there is a problem on the PC end.
8) Probe the return communication line while you give PMAC a command that requires a response (e.g. <CONTROL-
F>). If there is no action, you may have to change jumpers E9-E16 on PMAC to exchange the send and receive lines. If
there is action, but the host program does not receive characters, you may have RS-232 receiving circuitry that does not
respond at all to PMAC's RS-422 levels. If you have another model of PC, try using it as a test (most models accept
RS-422 levels quite well). If you cannot get your computer to accept the signals, you may need a level-conversion
device, such as Delta Tau's Accessory-26.
3.3.2 - Resetting PMAC for first time use
Once communications have been established, type the following commands in the terminal window:
$$$*** ;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