Specifications

Model 75A250A Manual Text
2-5
REV A
2.2.2 Remote Operation (continued)
2.2.2.4.2 IEEE-488 device address selection (continued)
Table 2-1
IEEE-488 Device Address Selection
Device Address Switch 5 Switch 4 Switch 3 Switch 2
Switch 1
1 off (0) off (0) off (0) off (0) on (1)
2 off (0) off (0) off (0) on (1) off (0)
3 off (0) off (0) off (0) on (1) on (1)
4 off (0) off (0) on (1) off (0) off (0)
5 off (0) off (0) on (1) off (0) on (1)
:
:
30 on (1) on (1) on (1) on (1) off (0)
2.2.2.5 Command Set Format
Each command is composed of one alpha character, up to four numeric parameters, and a
command termination character. The command termination character is the “line feed”
command, which is denoted and entered as <LF>. Commands are case-sensitive and must be
entered in upper case only in order to be recognized.
2.2.2.6 IEEE-488 Communications
For IEEE-488 communications, the “End or Identify” (EOI) control line may also be used for
command termination. When sending commands to the Model 75A250A via the IEEE-488 bus,
terminate each command with a <LF>, an EOI, or both. No characters are permitted after the
<LF> or EOI; the 75A250Ainterprets characters following the <LF> or EOI as the start of the
next command. When an error condition is present at the Model 75A250A, the
“Service Request” (SRQ) line is asserted; the operator can then perform a serial poll operation.
The Model 75A250A error code (in binary) is contained in the returned serial poll status byte
(STB). These error codes are defined in Table 2-2.