User manual

46 Using the Relay Multiplexer Chapter 2
120 OUTPUT 70914;"TRIG:SOUR TTLT1"
!Multiplexer to advance scan when trigger
received in TTL trigger bus line 1
130 OUTPUT 70914;"SCAN:MODE VOLT"
!Sets switchbox measurement to volt (used
to make 2-wire resistance measurement on
multimeter’s HI/LO terminals)
140 OUTPUT 70914;"SCAN:PORT ABUS"
!Closes control relays 992 and 993 connecting
the analog bus to the upper and lower four
bank commons
150 OUTPUT 70914;"SCAN (@100:177)"
!Defines channel list to scan bank 0 channel
0 to bank 7 channel 7
160 OUTPUT 70914;"*OPC?"
!Multiplexer operations complete
170 ENTER 70914;Opc
!Enters a "1" when complete
180 OUTPUT 70903;"READ?"
!Places multimeter in wait-for-trigger state.
Will send measurement results to output
buffer when triggered.
190 OUTPUT 70914;"INIT"
!Closes bank 0 channel 0 and enables the
scan. Causes a trigger output on TTL Trigger
bus line 0 that initiates the multimeter to
make a measurement.
200 ENTER 70903;Readings(*)
!Enters measurement results
210 PRINT Readings(*)
!Displays measurement result
220 END
!Terminates program
Example: Scanning
Channels Using E1412A
Multimeter
This example program uses the E1406A Command Module for one-wire
scanning of the E1460A using the two-wire ohms function of the E1412A
multimeter. The TTL trigger bus lines perform E1412A multimeter triggering
and E1460A multiplexer channel advance. This program uses the
stand-alone switchbox mode.
For this example, the following resistors are connected to the channels
indicated and to the one-wire COM terminal. The remaining channels are
open.
1 k on channel 00 HI
1.5 k on channel 00 LO
1.2 k on channel 01 HI
1.8 k on channel 01 LO
A typical result returns +0, "No error" for the response to the SYST:ERR?
command. The four channels with resistors connected return the nominal
value of the resistor, such as 1003.129 for channel 00 HI or 1489.102 for
channel 00 LO. All other channels return 9.9E+37 to indicate an open
channel.