SRS Labs SR530 manual Reset, Trouble-Shooting Interface Problems, Common Hardware Problems include

characters again.

Reset

The Z command resets the unit to its default state. The default front panel settings are listed in the DEFAULTS section of the Guide to Operations. In addition, the interface status returns to LOCAL, the SRQ mask is cleared, the RS232 character WAIT interval is set to 6, and the terminating sequence is reset to the proper defaults.

The command and output buffers are cleared by the Z command. Therefore, it is bad practice to use the Z command before all previous commands have been processed and all responses have been received.

Trouble-Shooting Interface Problems

If you are having difficulty getting your computer to communicate with the SR530 look to the sections on the RS232 and GPIB interfaces for some tips specific to your particular interface.

An ASCII terminal is a valuable aid for debugging interface problems. You can use it to:

1)become familiar with the SR530's command structure,

2)see GPIB bus transactions by using the GPIB echo mode,

3)eavesdrop on transactions when using the RS232 interface,

4)substitute a human for the SR530 by using a null modem cable ( to make the DTE a DCE) and attaching the terminal to the port to which you would normally have connected the SR530. This allows you to test your program's responses to inputs which you provide from the terminal.

Common Hardware Problems include:

1)The RS232 or GPIB cables are not properly attached.

2)The configuration switches for the RS232 characteristics or GPIB address are not set correctly (Make sure the RS232 echo is off when using the RS232 interface with a computer. The GPIB with RS232 echo

mode should be off when not debugging the GPIB interface.)

3)Your computer requires an RS232 control line to be asserted, but your cable does not pass it between the SR530 and the computer, or, your computer is not asserting the DTR line on the RS232.

Common Software Problems include:

1)You have sent the wrong command to ask for data from the SR530. Your program will wait forever for a response which is not going to come. This may not be your fault; we have seen Microsoft's Interpreted Basic on the IBM PC occasionally send a curly bracket (ASCII 253) when it was supposed to have sent a carriage return (ASCII 13).

2)Your computer's baud rate has been changed and no longer matches the SR530's baud rate.

3)The initial command sent to the SR530 was invalid due to a garbage character left in the command queue from power-up, or, the first character in you computer's UART is garbage, also due to power-up. It is good practice to send a few carriage returns to the SR530 when your program begins, and have your program clear-out its UART at the start of your program.

4)The SR530 is not sending the correct 'end-of- record' marker for your computer. For example, it appears that Microsoft's Rev 3.2 FORTRAN on the IBM PC under DOS 2.1 requires two carriage returns for an end-of-record marker. The J command can be used to set the SR530 end-of- record marker to 2 carriage returns. [The end-of-record marker is that sequence which indicates that the response is complete. From the keyboard, a single carriage return is the end-of-record marker.]

5)Answers are coming back from the SR530 too fast, overwriting the end-of-record markers, and causing the computer to hang waiting for a complete response. In this case, the W command can be used to slow down the response time of the SR530 preventing overwriting.

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