Martel Electronics DPC300A - Manual (Page 28)

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6. Remote Operation
6.1 Remote Interface
The calibrator can be remotely controlled using a PC terminal, or by
a computer program running the calibrator in an automated system.
It uses an RS-232 serial port connection for remote operation.
NOTE: To use the remote control option a custom RS-232
cable must be purchased from Martel (LEM232). To contact
Martel refer to Section 1.1 of this manual. With this connection
the user can write programs on the PC, with Windows languages like
Visual Basic to operate the calibrator, or use a Windows terminal,
such as Hyper Terminal, to enter single commands. Typical RS-232
remote configurations are shown in Figure 13.
REGULATOR
MAX 120 PSI
AIR SUPPLY 0-100 PSI
OUTPUT
-12-300 PSI
PUMP
-12-300 PSI
MEASURE
FINE ADJUST / VENT
PUMP
SELECTOR
MAIN
SELECTOR WARNING:
VENT BEFORE SELECTION
HOME
PUMP
ZERO
J1 J2 J3
COM
VOLTS /mA
SWITCH TEST +24v DC
PRESSURE MODULE
F1 F2 F3
FILTER
CHARGE
PRESSURE VACUUM
P2
P3
P4
MARTEL ELECTRONICS
DPC-300A
P1 P2 P3 P4
Figure 13. Calibrator-to-Computer Connection
6.2 Setting up the RS-232 Port for Remote Control
Note: The RS-232 connection cable should not exceed 15m unless
the load capacitance measured at connection points is less than
2500pF.
Serial parameter values:
9600 baud
8 data bits
1 stop bit
no parity
Xon/Xoff
EOL (End of Line) character or CR (Carriage Return) or both
The LEM232 cable is used for RS-232 communications from the
calibrator to a computer. If the computer only has USB type ports, a
USB to RS-232 converter will be needed. These can be obtained
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