User's Manual

PMAC User Manual
6 Getting Started with PMAC
Communications Baud Rate Jumpers
The PMAC was shipped configured to be able to communicate either over the bus interface, or over the
serial interface at 9600 baud. The communications setting is controlled by jumpers E44-E47 on the PMAC
PC, Lite, and VME, and by DIP switches SW1-5 to SW1-8 on the PMAC STD.
If communicating over the bus port for the initial setup of the board, the settings of these jumpers is not
important. However, if the initial communications is over the serial port, make sure these jumpers enable
the serial port and provide the baud rate desired. (The Setup program and Executive program do have
automatic baud rate search algorithms.
As sent from the factory, E44 and E47 should be OFF, while E45 and E46 should be ON (on PMAC STD,
SW1-5 and SW1-8 should be ON; SW1-6 and SW1-8 should be OFF). PMAC can receive commands
from both the bus and serial ports. (Keep commands on the two ports from overlapping.) PMAC powers
up or resets in a mode to respond over the serial interface, but any character received over the bus interface
changes the mode so it will respond over the bus interface instead. A <CTRL-Z> character received over
the serial port changes PMAC back to responding over the serial port. If the default jumper setting must be
changed, refer to the detailed E-point description.
PCbus Address Jumpers
PMAC PC and PMAC Lite are shipped from the factory set to communicate over the PC-bus at I/O address
528 decimal (210 hex). This setting is controlled by jumpers E91-E92 and E66-E71 located on the
rightmost of the lower-edge bank of jumpers (for this default address, E91-E92 are ON, E66 is OFF, E67-
E70 are ON, and E71 is off). Unless there is a conflict at this address, start using the first card at this
address. If the address must be changed, change the jumpers as shown in the detailed E-point descriptions
in the Hardware Reference manual.
STDbus Address Jumpers
PMAC STD is shipped from the factory set to communicate over the STD-bus at I/O address 61,584
decimal (F090 hex). This setting is controlled by jumpers W11 to W22 on the bottom circuit board (for
this default address, W11-W14 are OFF, W15-W18 are ON, W19 is OFF, W20-W21 are ON, and W22 is
OFF). Unless there is a conflict at this address, start using the first card at this address. If the address must
be changed, change the jumpers as shown in the detailed E-and W-point descriptions in the Hardware
Reference manual.
PMAC VME Interface Setup
The VMEbus interface is set up by writing to PMAC registers through the serial port. If using the PMAC
VME, the initial development is done by communicating to the PMAC over the serial port from an IBM-
PC or compatible host. Follow the directions for using the serial port. Information for setting up the VME
bus interface is provided in the Writing a Host Communications Program section of this manual.
Encoder Jumpers
PMAC can take either non-differential (single-ended A, B, C) or differential inputs (A, A/, B, B/, C, C/)
from encoders. As shipped from the factory, the card is set up for non-differential encoders, individually
selectable by jumpers E18-E21 (not available on PMAC Lite or PMAC STD) and E24-E27. In this setup
with pins 1 and 2 of each E-point connected, the main signal line is pulled up to +5V with a 470 ohm
resistor, and the complementary lines are held at +2.5V with 1 kohm pull-up and pull-down resistors,
allowing them to be a steady comparison point for the signal lines. If using single-ended encoders, leave
the complementary lines (A/, B/, and C/) floating, so PMAC can hold them at 2.5V. Do not ground these
inputs.