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Section 2: General operation
Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-88
2657A-901-01 Rev. B/December 2012
LOCAL key
The EXIT (LOCAL) key cancels the remote state and restores local operation of the instrument.
Pressing the EXIT (LOCAL) key also turns off the REM indicator and returns the display to normal if a
user-defined message was displayed.
If the LLO (Local Lockout) command is in effect, the EXIT (LOCAL) key is also inoperative. For safety
reasons, the OUTPUT ON/OFF control can be used to turn the output off while in LLO. Note that
pressing the EXIT (LOCAL) key or the OUTPUT ON/OFF control will also abort any commands or
scripts that are being processed.
RS-232 interface operation
This topic contains information about configuring RS-232 communication parameters, sending or
receiving command messages, and requesting or retrieving data. To control the Model 2657A,
connect a controller or personal computer to the Model 2657A RS-232 interface. Alternatively, you
can use the Model 2657A to control another device over RS-232.
Setting RS-232 interface parameters
To set interface parameters from the front panel:
1. Press
the
MENU
key, select
RS232
and then press the
ENTER
key or the navigation wheel
.
2. Select and enter the following interface parameters:
•
BAUD: Set baud rate (see
(on page 2-89))
•
BITS: Set number of bits (see
•
PARITY: Set parity
•
FLOW-CTRL:
Flow control and signal handshaking
(on page 2-89)
•
ENABLE: Enable or disable the RS-232 interface
3. Press
the
EXIT (LOCAL)
key twice to return to the normal display.
Remote RS-232 parameters
Commands to set RS-232 parameters are listed in the following table. See the
(on page 7-1) for more information.
RS-232 interface commands
Command Description
serial.baud = baud
Set baud rate (300, 600, 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200)
serial.databits = bits
Set number of bits (7 or 8)
serial.flowcontrol = flow
Set flow control:
serial.FLOW_NONE
(no flow control)
serial.FLOW_HARDWARE
(hardware flow control)
serial.parity = parity
Set parity:
serial.PARITY_NONE
(no parity)
serial.PARITY_EVEN
(even parity)
serial.PARITY_ODD
(odd parity)
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