User's Manual

PMAC User Manual
Talking to PMAC 35
<CTRL-H>
<CTRL-H> (backspace to erase last character sent) actually acts on the entire data stream as it is sent to
the cards. It erases the last alphanumeric character sent in the stream. Repeated <CTRL-H> characters
can erase all the alphanumeric characters sent since the latest carriage return character. If this includes
addressing characters, these are erased as well.
<CTRL-T>
Full duplex communication (echoing of characters) is not permitted in daisy-chained serial mode.
Therefore, the <CTRL-T> command (full/half-duplex toggle) will be rejected in this mode.
Resetting PMAC
There are several ways that PMAC can be reset. The first way is by cycling the 5V power off, then on.
The second way is by taking the INIT/ line on the JPAN connector low, then high. The third way is to
use the backplane-bus reset line. This method depends on the setting of jumper E39, and in PC-bus
versions, E93 and E94. The fourth method is to send the command to PMAC over either port.
PMAC Reset Actions
When PMAC receives the reset signal or command from any of these sources, it immediately stops all
active computations and starts its reset cycle. At the beginning of the reset cycle, it disables all outputs
and loads the firmware into active memory. It then proceeds to load active memory in a manner
dependent on the hardware configuration and the setting of re-initialization jumper E51. The PMAC
memory can be retained through a power-down or reset cycle with either EEPROM or battery-backed
RAM (the standard CPU section, which comes with the default configuration, Options 4 and 5), or
completely with flash memory (the Option CPU section, which comes with Options 4A, 5A, and 5B).
With the standard CPU section, the basic user card setup information (I-variables, conversion table
settings, VME and DPRAM address settings) are held in non-volatile EEPROM after being written there
with the SAVE command. User programs, tables, buffers, and definitions are simply retained in RAM by
the battery. No command or action is required to keep these items through a power-down or reset cycle.
With the Option CPU section, all user card information is held in non-volatile flash memory after being
written there with the SAVE command. No information is held in RAM through a power-down or reset
cycle, so the SAVE command must be used to keep any information in the card through a reset.
If jumper E51 is in its default state (OFF for PMAC PC, Lite, VME, and 1.5 STD; ON for PMAC STD),
PMAC copies the contents that were last saved into its non-volatile memory into active memory. For
PMACs with the standard CPU section, this involves just the items stored in the little EEPROM. Other
items are kept just as they were before the reset. For PMACs with the Option CPU section, this involves
all user settings: variables, definitions, programs, buffers, and tables.
All incremental encoder counters are set to zero during the reset cycle. At the end of the reset cycle, all
activated motors that have Ix80 set to 1 are enabled, with the commanded position set to the actual
position. Other motors are left in the killed state; these require a command to enable them at a future
time.
PMAC Re-initialization Actions: Standard CPU
If Jumper E51 is in its non-default state on a PMAC with the standard CPU section (ON for PMAC PC,
Lite, and VME; OFF for PMAC STD), PMAC performs a re-initialization during the reset cycle. Instead
of copying saved values of parameters from EEPROM into active memory, it copies the factory default
values from the firmware PROM into active memory.