Reference Manual

PMAC 2 Software Reference
46 PMAC I-Variable Specifiation
I65 User-Configuration Variable
Range
0 – 16,777,215
Units
None
Default
0
Remarks
I65 is an I-variable that has no automatic use on PMAC. The purpose of this variable is to
provide an easy way for the user to confirm that the application configuration has been
loaded into the PMAC. Since the factory default value for I65 is 0, setting I65 to a non-
zero value as part of the configuration permits an easy way to verify that the configuration
file has been downloaded.
By providing many different possible non-zero values of I65, different machine
configurations can be identified with I65. It is even possible for the user to utilize I65 as
an electronic serial number.
I66 Servo-Channel ADC Auto-Copy Disable {PMAC2 only}
Range
0 .. 1
Units
None
Default
0
Remarks
I66 permits the disabling of the PMAC2 function that automatically copies the values in
the 16 A/D-converter registers (A and B registers of Channels 1 – 8) of the two
“DSPGATE1” Servo ICs into RAM every phase cycle. This auto-copying function was
implemented because in the early revisions of the DSPGATE1 IC, the ADC registers
themselves could only be read reliably during phase-interrupt tasks.
Note:
This function is not to be confused with de-multiplexing of Option
12 or ACC-36 ADCs controlled by I60 and I61 on a PMAC(1) or
the analog table on a PMAC2.
Recent revisions of the DSPGATE1 IC (“B” revision and newer), installed on virtually all
PMAC2 boards starting in the year 2000, double buffer these registers so that they may be
read properly at any time. Therefore, this auto-copying function is not necessary in most
cases on newer boards.
If I66 is set to the default value of 0, at the beginning of each phase cycle, PMAC2 copies
the values found at these 16 addresses (whether physically present or not) into RAM
registers at X/Y:$0710 – X/Y:$0717.
If I66 is set to 1, PMAC2 does not perform this copying function each phase cycle. The
user may want to disable the copying for two reasons. First, it saves significant amounts of
processor time. Second, the auto-copying process interferes with the operation of an ACC-
51P board that is mapped into Channels 1 – 4 or 5 – 8. (It does not interfere with an ACC-
51P board mapped into Channels 9 – 12 or 13 – 16.)
I66 is used at power-up/reset only. To enable or disable the auto-copying function, change
the value of I66, issue the SAVE command, then reset the card. If you wish to temporarily
enable or disable this function, change the internal control bit at X:$0003 bit 15.
Note:
The P2Setup PC program, when used to set up digital current loop
operation for on-board servo channels (not through MACRO),