Status Byte Definition
Bit Meaning
0Magnitude too small to calculate phase
1Command Parameter is
2No detectable reference input
3PLL is not locked to the reference
4Signal Overload
5
6SRQ generated
7Unrecognized 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 SwitchesBit | 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
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 SR510.
7