User`s manual

Table C-2. Command and Parameter Opcodes (continued)
Multimeter
Parameter
Command
Opcode
Parameter
Opcode Value
Query
Opcode
Query
Response
Voltmeter
Complete Signal
Destination
40 8-bit binary number
(7)
0 - 7
(TTL trigger lines)
41 8-bit binary number
Sample Count 38 <upper byte>
<middle byte>
<lower byte>
1 - 16,777,215
(1),(4)
32 24-bit unsigned
number
(2)
Sample Source 07 00
01
02
03
Immediate
Timer
Software
Control Register
30 parameter
opcode
Sample Period
(5)
10 <upper byte>
<lower byte>
76µs - 65.534ms (1)
11 16-bit unsigned
number
(2)
Software Sample
(6)
35 —- —- —- ...
Trigger Arm 12 00
01
Un-armed
Armed
—- —-
Trigger Immediate 13 —- —- —- ...
Send Error 15 —- —- —- —-
(1) Specified as a 2’s complement binary number. For three byte parameters <upper byte> = value shifted 16 bits to the
right (>>16), <middle byte> = value shifted 8 bits to the right (>>8), <lower byte> = value. For two byte parameters
<upper byte> = value shifted 8 bits to the right (>>8), <lower byte> = value & 0xFF.
(2) Reading the Query Response Register two times (16-bit number) or three times (24-bit number) returns in order; the
high byte, middle byte, and low byte.
(3) A parameter value of 0 sets infinite triggers per trigger arm.
(4) A parameter value of 0 sets infinite samples per trigger.
(5) Set when Sample Source is Timer.
(6) Used when Sample Source is Software. The first measurement of each burst occurs when the trigger signal is
received (e.g. Trigger Immediate). Subsequent measurements in the burst occur when Software Sample is written to the
Command Register.
(7) Up to seven VXIbus TTLTrg trigger lines can be selected. 01 selects line 0, FF selects all lines.
Appendix C HP E1326B/E1411B Multimeter Register-Based Programming 263