Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Turbo PMAC General Purpose I/O Use
199
Multiplexer Port Accessories
Delta Tau provides several accessories that can connect to the JTHW multiplexer port, with automatic
firmware support for accessing the I/O on these boards. These accessories provide a direct flat-cable
connection to the JTHW port, and the port is configured automatically at power-up/reset to work with any
of these boards. These accessories include:
firmware support for accessing the I/O on these boards. These accessories provide a direct flat-cable
connection to the JTHW port, and the port is configured automatically at power-up/reset to work with any
of these boards. These accessories include:
•
Acc-8D Opt. 7 Resolver-to-Digital Converter Board
•
Acc-8D Opt. 9 Yaskawa Absolute Encoder Interface Board
•
Acc-18 Thumbwheel Board (obsolete)
•
Acc-34x 32-Input 32-Output Boards
For the Acc-8D Option 7 and Acc-8D Option 9 boards, special settings of Ixx91 and Ixx95 support
absolute position reads from these devices. There is also special M-variable formats for accessing I/O
data on most of these boards:
absolute position reads from these devices. There is also special M-variable formats for accessing I/O
data on most of these boards:
•
Acc-8D Opt. 7: TWS-format M-variables for absolute position data
•
Acc-18: TWD-format M-variables for binary-coded decimal reads of digits
•
Acc-34x: TWS-format M-variables for serial access of 32-bit input or output word
Hardware Characteristics
When configured as an output, each line on the multiplexer port has a 5V CMOS totem-pole driver. This
driver can sink or source up to 20 mA. There is a 10 k
driver can sink or source up to 20 mA. There is a 10 k
Ω pull-up resistor to 5V on each line for input
purposes, but the driver IC can hold the line high or low despite this resistor. When configured as an
input, the buffer IC presents a high-impedance input either sinking or sourcing; no significant current will
flow. The pull-up resistor on the line will bias the line high in the absence of anything actively pulling
the line low at significantly lower impedance.
input, the buffer IC presents a high-impedance input either sinking or sourcing; no significant current will
flow. The pull-up resistor on the line will bias the line high in the absence of anything actively pulling
the line low at significantly lower impedance.
Suggested M-Variables
The 16 I/O lines are memory-mapped into PMAC’s address space in register Y:$078402. Typically these
lines are used as a unit with specially designed multiplexing I/O accessories and appropriate multiplexing
M-variables (TWB, TWD, TWR, and TWS formats), in which case Turbo PMAC handles the direct control
of these I/O lines automatically. However, these lines can also be accessed individually with M-variables.
The complete list of M-variables is shown in the Software Reference Manual; a few are shown here:
lines are used as a unit with specially designed multiplexing I/O accessories and appropriate multiplexing
M-variables (TWB, TWD, TWR, and TWS formats), in which case Turbo PMAC handles the direct control
of these I/O lines automatically. However, these lines can also be accessed individually with M-variables.
The complete list of M-variables is shown in the Software Reference Manual; a few are shown here:
M40->Y:$078402,8
; SEL0 Line; J2 Pin 4
…
M47->Y:$078402,15
; SEL7 Line; J2 Pin 18
M48->Y:$078402,8,8,U
; SEL0-7 Lines treated as a byte
M50->Y:$078402,0
; DAT0 Line; J2 Pin 3
…
M57->Y:$078402,7
; DAT7 Line; J2 Pin 17
M58->Y:$078402,0,8,U
; DAT0-7 Lines treated as a byte
Direction Control
In the default configuration automatically set at power-up/reset, DAT0 to DAT7 are set up as non-
inverting inputs; SEL0 to SEL7 are set up as non-inverting outputs with a zero (low voltage) value. If
any of the multiplexer port accessories are to be used, this configuration must not be changed.
inverting inputs; SEL0 to SEL7 are set up as non-inverting outputs with a zero (low voltage) value. If
any of the multiplexer port accessories are to be used, this configuration must not be changed.
The direction control bit for each of these I/O bits is in the corresponding bit in the matching X register.
For example, the direction control bit for DAT3 is located at X:$078402,3; the direction control bit for
SEL6 is located at X:$078402,14. Because the buffer ICs can be switched only by byte, it is best to
define 8-bit M-variables for the direction control. Suggested definitions are:
For example, the direction control bit for DAT3 is located at X:$078402,3; the direction control bit for
SEL6 is located at X:$078402,14. Because the buffer ICs can be switched only by byte, it is best to
define 8-bit M-variables for the direction control. Suggested definitions are:
M60->X:$078402,0,8
; Direction control for DAT0 to DAT7
M62->X:$078402,8,8
; Direction control for SEL0 to SEL7