User`s guide

4-34
Programming
Programming Examples
Example 2: Switch position using the Status Byte Regis-
ter
This program is identical in functionality to the first sample program except a
different method is used for determining when the switch has settled. The set-
tling routine used here reads the Status Byte Register repeatedly until bit
0 returns to zero.
Listing 10 INTEGER Switch_addr,A_position,B_position,
Status_byte
20 DIM Command$[80],Channel$[80],Error_return$[80]
30 Switch_addr=711
40 CLEAR SCREEN
50 INPUT "Enter A-port position : ",A_position
60 INPUT "Enter B-port position : ",B_position
70 Channel$="A"&TRIM$(VAL$(A_position))&",B"&TRIM$
(VAL$(B_position))
80 Command$="ROUTE:LAYER1:CHANNEL "&Channel$
90 OUTPUT Switch_addr;Command$
100 GOSUB Wait_to_settle
110 REPEAT
120 OUTPUT Switch_addr;"SYSTEM:ERROR?"
130 ENTER Switch_addr;Error_return$
140 PRINT Error_return$
150 UNTIL (VAL(Error_return$)=0)
170 GOTO Exit_prog
180 !
190 Wait_to_settle: ! wait for switch to settle
200 REPEAT
210 OUTPUT Switch_addr;"*STB?"
220 ENTER Switch_addr;Status_byte
230 UNTIL NOT BIT(Status_byte,0)
240 RETURN
250 !
260 Exit_prog:!
270 END