User's Manual
Table Of Contents
- 45 Dual Display Multimeter
- 1. Introduction
- 2. Getting Started
- 3. Operating the Meter From the Front Panel
- 4. Applications
- 5. Operating the Meter Using the Computer Interface
- Introduction
- Preparing the Meter for Operations via the RS-232 Interface
- Preparing the Meter to be Operated via IEEE-488 Interface
- Getting Started With An Installation Test
- How the Meter Processes Input
- How the Meter Processes Output
- Triggering Output
- Service Requests (IEEE-488 Only and Status Registers
- Computer Interface Command Set
- IEEE-488 Capabilities and Common Commands
- Function Commands and Queries
- Function Modifier Commands and Queries
- Range and Measurement Rate Commands and Queries
- Measurement Queries
- Compare Commands and Queries
- Trigger Configuration Commands
- Miscellaneous Commands and Queries
- RS-232 Remote/Local Configurations
- Sample Program Using the RS-232 Computer Interface
- Sample Programs Using the IEEE-488 Computer Interface
- 6. Maintenance
- Appendices

Operating the Meter Using the Computer Interface
Computer Interface Command Set
5
5-23
Table 5-12. Function Modifier Commands and Queries
Command Description
Meter enters decibels modifier. Any reading shown in the primary display is in
decibels.
An Execution Error is generated if the meter is not in a volts ac and/or dc function.
Meter exits the decibels modifier and displays readings in normal units. Also clears dB
Power, REL, and MN MX modifiers.
Meter enters dB Power modifier if the reference impedance is set to 2, 4, 8, or 16
ohms and a voltage function has been selected. Otherwise an Execution Error is
generated. In dB Power, readings shown in the primary display are in Watts.
Set dB reference impedance to a <value> shown in Table 5-10A. This value
corresponds to the reference impedance (ohms) indicated.
If <value> is not a value in Table 5-10A, an Execution Error is generated.
Table 5-12A. Reference Impedance Values
Value Ref Impedance Value Ref Impedance
1
2
3
4
5
6
7
8
9
10
11
2
4
8
16
50
75
93
110
124
125
135
12
13
14
15
16
17
18
19
20
21
150
250
300
500
600
800
900
1000
1200
8000
DB
DBCLR
DBPOWER
DBREF <value>
DBREF?
HOLD
HOLDCLR
HOLDTHRESH
<threshold>
HOLDTHRESH?
MAX
Meter returns a <value> shown in Table 5-11A. This value corresponds to the
reference impedance indicated.
Meter enters Touch Hold modifier. (See "HOLD Modifier" in Chapter 3 for more on
Touch Hold.) If HOLD is sent when the meter is already in Touch Hold, a reading is
forced and shown on the display.
Meter exits Touch Hold and restores display to normal operation.
Set HOLD measurement threshold to <threshold>. <threshold> must be "1" (very
stable), "2" (stable), or "3" (noisy). Any other value generates an Execution Error. See
"HOLD Modifier" in Chapter 3.
Meter returns Touch Hold <threshold> (i.e., "1", "2", or "3"). See "HOLD Modifier" in
Chapter 3 for a description of Touch Hold thresholds.
Meter enters MN MX modifier with present reading as maximum value. If already in
MN MX modifier, meter displays maximum value. In MN MX modifier, autoranging is
disabled. See "MN MX Modifier" in Chapter 3.