Meade Instruments 1697 Computer Drive System For LXD 650 and LXD 750 Mounts - Part 2 User Manual

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2. CDS Test Program

Once you have the RS-232 cable constructed, you will want to test the cable. Below is a simple program
called "CDS TEST” that is written in GW Basic programming language and will work with virtually any IBM
compatible computer. CDS Test is an effective program to fully check the RS-232 line communications from
your personal computer to the CDS, allowing you to concentrate on de-bugging your RS-232 cable.

To enter the following program, first load BASIC or GWBASIC (which ever your computer system uses), then
type in the following program. When complete, be sure to save the program as “CDSTST.BAS.”

10 CLS

20 DEFINT A-X

30 OPEN "COM1:9600,N,8,1,CD0,CS0,DS0,RS," FOR RANDOM AS #1

50 key1$ = INKEY$: IF key1$ = "" THEN GOTO 50

60 REM KEY1S

70 IF key1$ = CHR$(119) THEN GOSUB 200: REM "w" key

80 IF key1$ = CHR$(101) THEN GOSUB 200: REM "e" key

90 IF key1$ = CHR$(110) THEN GOSUB 200: REM "n" key

100 IF key1$ = CHR$(115) THEN GOSUB 200: REM "s" key

105 IF key1$ = "x" THEN END: REM To exit test.

110 GOTO 50

120 END

200 REM directions

210 REM west

220 IF key1$ = "w" THEN a$ = "#:Mw#": PRINT #1, a$: REM GO west

230 REM east

240 IF key1$ = "e" THEN a$ = "#:Me#": PRINT #1, a$: REM GO east

250 REM north

260 IF key1$ = "n" THEN a$ = "#:Mn#": PRINT #1, a$: REM GO north

270 REM south:

280 IF key1$ = "s" THEN a$ = "#:Ms#": PRINT #1, a$: REM GO south

290 key1$ = INKEY$:

300 IF key1$ = CHR$(32) THEN GOTO 400 ELSE GOTO 200

400 REM This stops motion (by hitting SPACE bar).

410 B$ = "#:Qe#": PRINT #1, B$

420 B$ = "#:Qw#": PRINT #1, B$

430 B$ = "#:Qn#": PRINT #1, B$

440 B$ = "#:Qs#": PRINT #1, B$

450 RETURN

460 END

To use the above program, connect the completed cable to your PC serial port and to the CDS RS-232 Port.
Load BASIC (or GWBASIC), if not already loaded, and run “CDSTST.BAS.” Nothing will appear on the
computer screen. Press any one of the N, S, E, or W (lower case) keys on your PC keyboard, this will move
the LXD mount North, South, East, or West respectively. Press the space bar on the PC keyboard to stop.
Press X to exit the program.

If the LXD mount does not respond to the N, S, E, or W keys, be sure the CAPSLOCK is OFF. If it still does
not work, check the PC serial port pinouts for your computer to be sure they are wired correctly to the CDS
6 line connector.

With a successful check-out of the PC link with the CDS using “TEST”, you are now ready to write your own
software program using the CDS Command Set, or to use the sample program called “DEMO” that is written
in Quick Basic software language.