D U N I W A Y S T O C K R O O M C O R P .
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O. Serial Interface
The RS-232 serial port gives pressure readings when requested by the terminal. The interface is
standard RS-232 format; 9600 baud, 8-bits, no parity, 1 stop bit. The interface is through the 15-
pin D-sub accessory connector, see Figure 8, page 12.
pin 7 is Tx (signal from the 908A to the terminal)
pin 8 is Rx (signal from the terminal to the 908A)
pin 9 is return (ground).
The serial port allows reading pressure and other parameters of the 908A; it is not possible to
modify stored parameters over the serial port.
Figure 14: Serial Interface Cables from PC to Terranova 908A
The following commands are used in the 908A:
1. Pressure
To read the pressure of both gauges
Send “p” (ASCII value 112); the 908A sends pressure for gauge 1 and gauge 2 to the terminal.
Output is in the format:
ABCD
e
E FGHI
e
J
where
ABCD
is the multiplier and
E
is the exponent for CDG #1
FGHI
is the multiplier and
J
is the exponent for CDG #2
Some examples follow:
TELEPHONE: 650-969-8811 TOLL-FREE (U.S. only): 800-446-8811 FAX: 650-965-0764 EMAIL: [email protected]
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