SRS Labs SR530, Lock-In Amplifier manual 120′

Program Example 4: IBM PC,Microsoft Basic, via GPIB

This program requires the Capital Equipment Corporation GPIB card for the IBM PC or XT. It has firmware in ROM to interface high level languages to the GPIB.

Subroutine calls in Microsoft BASIC are done to memory locations specified by the name of the subroutine. The address is relative to the segment address specified by the DEF SEG statement preceding CALL.

In this program, the CEC card's ROM starts at OC0000H, the system controller's address is 21, and the SR530 has been assigned as GPIB address 23.

To monitor the GPIB activity with an RS232 terminal, SW1-6 should be down, and the ASCII terminal should be attached to the rear panel RS232 connector.

10 ′ EXAMPLE PROGRAM TO READ THE SR530 OUTPUT AND RAMP THE X6 ANALOG OUTPUT 20 ′ USING IBM PC BASICA AND THE CAPITAL EQUIPMENT CORP. GPIB INTERFACE CARD

30′

40 ′ THE RAMP ON X6 CAN BE MATCHED BY SETTING THE SR530 DISPLAY TO D/A.

50′

60 ′ ON THE SR530 REAR PANEL, SET SWITCHES #4 AND #6 ON SW1 TO DOWN (DEVICE 70 ′ ADDRESS = 23, RS232 ECHO ON) AND SWITCH # 1 ON SW2 TO DOWN (RS232 BAUD 80 ′ RATE = 9600). ALL OTHER SWITCHES SHOULD BE UP.

90 ′ NOTE THAT THE RS232 ECHO IS FOR DEBUGGING AND DEMOSTRATION PURPOSES,

100 ′ UNDER NORMAL CONDITIONING, SWITCH # 6 OF SW1 SHOULD BE UP SINCE THE RS232 110 ′ ECHO SLOWS DOWN THE GPIB INTERFACE.

120′

130	DEF SEG = &HC000	′BASE ADDRESS OF CEC	CARD
140	INIT=0: TRANSMIT=3:	RECV=6: ′ADDRESSES OF CEC FIRM WARE ROUTINES
150	ADDR%=21: SYS%=0	′CONTROLLER	ADDRESS

160INZ$ = ″IFC UNT UNL MTA LISTEN 23 DATA ′Z′ 13″

170′

180Q1$ = ″IFC MTA LISTEN 23 DATA ′Q1′ 13″

190Q2$ = ″IFC MTA LISTEN 23 DATA ′Q2′ 13″

200X6$ = ″IFC MTA LISTEN 23 DATA ′X6, ″

210LISN$ = ″IFC UNT UNL MLA TALK 23″

220′

230′

240	CALL	INIT(ADDR%,SYS%)	′INIT X6 OUTPUT		TO ZERO
250	CALL	TRANSMIT(INZ$,STATUS%)	′RESET	SR530	STATUS
260	GOSUB 600		′CHECK	TRANSMIT

270′

280 X = 0 ′INIT X6 OUTPUT TO ZERO

290′

300	CALL	TRANSMIT(Q1$,STATUS%)	′READ CHANNEL 1 OUTPUT
310	GOSUB 600		′GET RESULT
320	GOSUB 510
330	V1 =	VAL(ANS$)	′INTO V1

340′

350	CALL	TRANSMIT(Q2$,STATUS%)	′READ CHANNEL 2 OUTPUT
360	GOSUB 600		′GET RESULT
370	GOSUB 510
380	V1 =	VAL(ANS$)	′INTO V2

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