Santec PEM-320, Руководство по эксплуатации

Страница: 30 / 46

POLARIZATION EXTINCTION RATIO METER PEM-320
8-3
8.3. Control Commands
The table below lists the control commands specific to the PEM-320 which can be implemented
using either the GPIB or RS-232C protocols. A command consists of two letters and may be written
in either upper or lower case. As appropriate, the commands can be issued with or without a
numerical suffix. A delimiter must be attached to the end of each command to ensure correct
execution and termination of each command line. The delimiter required for GPIB operation is
CR+LF. The delimiter required for RS-232C operation can be CR, LF or CR+LF. This delimiter is
set in the factory to CR and this can be changed during the ‘Power On’ procedure; for details see
Section 7.1 Power On.
To read data from the PEM-320 it is first necessary to set the output parameter to the required data
parameter. When subsequent read commands are issued the data corresponding to the set parameter is
read. In RS-232C communication “echo-back” is used to verify correct communications. Once the
output parameter has been set the DI command is used to request data from the unit. In both GPIB and
RS-232C protocols when a command is issued that cannot be interpreted the PEM-320 outputs “NR” to
the next data request. This output stops when a valid command is received.
Command Description Format
OC Offset cancel command. OC
PE Sets output variable to indicate PER (dB). PE
DP Sets output variable to indicate optical power (dBm). DP
WP Sets output variable to indicate optical power (mW). WP
AG Sets output variable to indicate polarization angle (deg). AG
Sets measurement speed to 2.5Hz. RF0
Sets measurement speed to 5Hz. RF1
Sets measurement speed to 10Hz. RF2
TP Sets output variable to indicate peak measured power. TP
BP Sets output variable to indicate minimum measured power. BP
RF