Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Talking to Turbo PMAC
41
Auxiliary Port Parser Disable
It is possible to turn off the automatic command parser on the auxiliary serial port by setting I43 to 1.
With I43 set to the default value of 0, Turbo PMAC will try to interpret any characters coming in the
auxiliary serial port as part of Turbo PMAC commands. However, with I43 set to 1, these characters are
just placed in the rotary command queue at X:$1C00 – X:$1CFF, where a user’s application program can
interpret them.
It is possible to turn off the automatic command parser on the auxiliary serial port by setting I43 to 1.
With I43 set to the default value of 0, Turbo PMAC will try to interpret any characters coming in the
auxiliary serial port as part of Turbo PMAC commands. However, with I43 set to 1, these characters are
just placed in the rotary command queue at X:$1C00 – X:$1CFF, where a user’s application program can
interpret them.
It is not possible to download new operational firmware through the auxiliary serial port.
Signal Format
Since serial interfaces vary from system to system, Turbo PMAC provides a simple but flexible interface.
In addition to the signal ground line, only four lines are required (eight if counting the complements in an
RS-422 interface): data-transmit, data-receive, clear-to-send, and ready-to-send. Turbo PMAC serial
ports simply short together the DSR and DTR handshake lines to provide an automatic return signal on
this strobe for those systems that require it.
In addition to the signal ground line, only four lines are required (eight if counting the complements in an
RS-422 interface): data-transmit, data-receive, clear-to-send, and ready-to-send. Turbo PMAC serial
ports simply short together the DSR and DTR handshake lines to provide an automatic return signal on
this strobe for those systems that require it.
The send and receive signals, for both data and handshake, are placed on the connector in the Data
Terminal Equipment (DTE) configuration (on the Turbo PMAC-PC, this can be changed using jumpers
E9 – E16). This permits a straight-across connection to the serial port configured as Data
Communications Equipment (DCE), which is the configuration found on virtually all modern computers.
However, if connecting the serial port to another device configured as DTE, such as a handheld
terminal/pendant, cross the data and handshake signals.
Terminal Equipment (DTE) configuration (on the Turbo PMAC-PC, this can be changed using jumpers
E9 – E16). This permits a straight-across connection to the serial port configured as Data
Communications Equipment (DCE), which is the configuration found on virtually all modern computers.
However, if connecting the serial port to another device configured as DTE, such as a handheld
terminal/pendant, cross the data and handshake signals.
The pin-outs of the box-header connectors used for the serial ports on most Turbo PMACs are designed
so that a flat-cable connection to a D-sub connector on the other end will provide the proper connection if
the other end is in DCE configuration.
so that a flat-cable connection to a D-sub connector on the other end will provide the proper connection if
the other end is in DCE configuration.
Data Format and Handshaking
The serial communications data format for each character is 8 bits, 1 start bit, 1 stop bit, no parity. (There
may be an option to permit parity in future firmware revisions.) No full-duplex echoing of characters is
supported.
may be an option to permit parity in future firmware revisions.) No full-duplex echoing of characters is
supported.
RTS/CTS handshaking is enabled by default. Because of Turbo PMAC’s very high speed in handling
communications, it will never hold off a character unless it is locked in a reset or watchdog state. Turbo
PMAC will ignore the CTS handshake from the host computer on the main serial port if I1 is set to 1 or 3,
but in this case ensure high-priority monitoring of the serial port to make sure that no characters are lost
(standard Microsoft Windows serial drivers do not have high enough priority for this).
communications, it will never hold off a character unless it is locked in a reset or watchdog state. Turbo
PMAC will ignore the CTS handshake from the host computer on the main serial port if I1 is set to 1 or 3,
but in this case ensure high-priority monitoring of the serial port to make sure that no characters are lost
(standard Microsoft Windows serial drivers do not have high enough priority for this).
Most Turbo PMAC serial ports short together the DSR and DTR lines to provide an echo handshake on
those ports that require this. No XON/XOFF software handshaking is supported.
those ports that require this. No XON/XOFF software handshaking is supported.
Multi-Drop Communications
With an RS-422 serial port, it is possible to communicate with multiple daisy-chained Turbo PMACs
over a single multi-drop cable. Up to 16 Turbo PMACs can be addressed on a single cable.
over a single multi-drop cable. Up to 16 Turbo PMACs can be addressed on a single cable.
I-Variable Enabling
Turbo PMAC variable I0 determines the controller’s software address on a multi-drop serial cable. I0 has
a range of 0 to 15 (0 to F hex). Each controller on the cable must have a unique value of I0. Variable I1
on each Turbo PMAC must be set to 2 or 3 to enable the serial software addressing.
Turbo PMAC variable I0 determines the controller’s software address on a multi-drop serial cable. I0 has
a range of 0 to 15 (0 to F hex). Each controller on the cable must have a unique value of I0. Variable I1
on each Turbo PMAC must be set to 2 or 3 to enable the serial software addressing.