Reference Manual

PMAC 2 Software Reference
PMAC On-Line Command Specification 259
Syntax
M{constant}[..{constant}]->TWR[:]{multiplex address}, {offset}
where:
• {constant} is an integer from 0 to 1023 representing the number of the M-variable;
• the optional second {constant} must be at least as great as the first {constant} – it
represents the number of the end of the range;
• {multiplex address} is an integer constant, divisible by 2, in the range 0 to 254,
representing the address in the multiplexing scheme of the ACC-8D Option 7 resolver-to-
digital converter board on the thumbwheel multiplexer port, as determined by the DIP
switch settings on the board
• {offset} is an integer constant from 0 to 7, representing the location of the device at
the specified multiplexer address, as determined by in the buffer on the ACC-8D Option
7 and the actual pins to which the device was wired.
Note:
No spaces are permitted between the M-variable name and the arrow
double character in this command
Remarks
This command causes PMAC to define the specified M-variable or range of M-variables to
point to a 12-bit word from a resolver-to-digital (R/D) converter or similar device serially
multiplexed on the “thumbwheel” port on an ACC-8D Option 7 or compatible board.
The address on the multiplex port specified here must match the address set by the DIP
switches on board the ACC-8D Opt-7. The ACC-8D Opt-7 manual contains a table listing all
of the possibilities.
One of the DIP switches on the ACC-8D Opt-7 board determines whether the R/D converters
on board have offset values of 0 to 3 or 4 to 7. The {offset} specifier must match this
DIP switch setting and the number of the R/D device on the board.
This is a read-only M-variable format. Use of this variable in an on-line query command or a
program statement will cause PMAC to clock in 12 bits of unsigned data (range 0 to 4095)
from the specified device through the multiplexer port.
Note:
It is not necessary to use an M-variable to access an R/D converter for
actual servo or phasing feedback purposes. I-variables (Ix10, Ix81,
I8x, I9x) are used for that purpose. However, even if this is your only
use of the R/D converter, it is usually desirable to assign M-variables
to the R/D converters for set-up and diagnostic purposes.
Example
M100->TWR:0,0
M99->TWR:4,5
M{constant}->TWS:{address}
Function
Serial Thumbwheel-Multiplexer M-Variable Definition
Scope
Global
Syntax
M{constant}[..{constant}]->TWS[:]{multiplex address}
where:
• {constant} is an integer from 0 to 1023 representing the number of the M-variable;
• the optional second{constant} must be at least as great as the first {constant} – it
represents the number of the end of the range;
• {multiplex address} is an integer constant, divisible by 4, in the range 0 to 124,
representing the address in the multiplexing scheme of the first of four bytes in the 32-bit