8
Status Byte Definition
Bit Meaning
0 Magnitude too small to calculate
phase
1 Command Parameter is out-of-range
2 No detectable reference input
3 PLL is not locked to the reference
4 Signal Overload
5 Auto-offset failed: signal too large
6 SRQ generated
7 Unrecognized or illegal command
Configuration Switches
There are two banks of 8 switches, SW1 and
SW2, located on the rear panel. SW1 sets the
GPIB address and SW2 sets the RS232
parameters. The configuration switches are read
continuously and any changes will be effective
immediately.
SW1:GPIB Mode Switches
Bit Example Function
1 } up GPIB Address Switches
2 } up Address 0 to 30 allowed
3 } up 'up' for bit = 1
4 } down 'down' for bit = 0
5 } up (Most Significant Bit)
6 down 'down' to echo on RS232
(normally 'up')
7 up Not Used
8 up Not Used
If the GPIB mode switches are set as shown in the
example column above, then the lockin will be
addressed as GPIB device #23, and all GPIB
commands and data will be echoed over the
RS232 for de-bugging purposes.
SW2:RS232 Mode Switches
Bit 1 Bit 2 Bit 3 Baud Rate
up up up 19200
down up up 9600
up down up 4800
down down up 2400
up up down 1200
down up down 600
up down down 300
Bit Setting Explanation
4 up Odd parity
down Even parity
5 up No parity
down Parity enabled
6 up No echo (for computer)
down Echo mode (for terminal)
7 up Two stop bits
down One stop bit
8 unused
Eight data bits are always sent, regardless of the
parity setting. The most significant bit is always
zero.
Example: Bit 1 'down' and all others 'up' for
RS232 communication at 9600 baud, no parity,
two stop bits, and no echo or prompts by the
SR530.