JDS Uniphase BACKREFLECTION METER RM3750 User Manual - Programming Guide
RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
10112341 Rev 002
Page 37 of 39
Programming Guide
RS232 Serial Interface
The RM meter is equipped with an RS232 serial interface. Through the RS232 connection, the
user can download measured values of backreflection, loss, and power to a computer or
printer. The RM meter can also use an IEEE 488 parallel interface through the external RS232-
to-IEEE 488 converter (described in the RS232-GPIB Converter section).
The RS232 serial interface is configured as data terminal equipment (DTE). The data protocol
is set to 2400 baud, ASCII character code with eight bits per character, two stop bits, and no
parity bit.
RS232 Pin Assignment
The RS232 pin assignment is shown in Figure 11.
Figure 11: RS232 Pin Assignment
RS232 Interface Specifications
The RS232 interface specifications are listed in Table 8.
Table 8: RS232 Interface Specifications
Name
Symbol
Pin Number
Signal Direction
Transmitted data
TxD
2
→
Received data
RxD
3
←
Request to send
RTS
8
→
Clear to send
CTS
7
←
Data carrier detect
DCD
4
←
Data terminal ready
DTR
6
→
Signal ground
SG
5
↔
To connect the RM meter to the serial port of a computer:
1. Attach
a
straight-through RS232 cable to the computer and the RS232C port at the back of
the meter.