Tektronix DMM4020 Digital-Multimeter, DMM, VFD-Multiple segment, 20000 counts CAT II 600 V DMM4020-A1 Data Sheet
Product codes
DMM4020-A1
Operating the Meter Using the Computer Interface
Introduction
4
4-3
Introduction
This chapter describes how to set up, configure and operate the Meter via the RS-232
computer interface on the Meter’s rear panel. The Meter can be operated from a host (a
terminal, controller, PC, or computer) by sending commands to the Meter through its
computer interface.
An annotated sample program illustrating the use of the RS-232 computer interface is
An annotated sample program illustrating the use of the RS-232 computer interface is
provided at the end of this chapter. Refer to Chapter 3 for complete descriptions of all
Meter functions and features.
This chapter assumes that you are familiar with the basics of data communication and
This chapter assumes that you are familiar with the basics of data communication and
RS-232 interface.
Local and Remote Operations
When the Meter is operated from a host, it is said to be operated remotely. When the
Meter is operated from its front panel, it is said to be operated locally.
Most operations that can be performed locally can also be performed remotely using the
Most operations that can be performed locally can also be performed remotely using the
computer interface. Some operations, like setting communications parameters for the RS-
232 interface operations, can only be performed from the front panel.
Computer Interfaces
The Meter comes equipped with an RS-232 (serial) interface. Using the interface turns
the Meter into a fully programmable instrument that can be integrated into an automated
instrumentation system.
Preparing the Meter for Operations via the RS-232 Interface
The RS-232 interface allows ASCII asynchronous serial communication between the
Meter and a host, serial printer or terminal.
Setting Communication Parameters (RS-232)
Table 4-1 provides the RS-232 communication parameters factory settings. Setting RS-
232 communication parameters is only performed through the front panel.
In order for the Meter and host to communicate via the RS-232 interface, the
In order for the Meter and host to communicate via the RS-232 interface, the
communication parameters of the Meter must match those of the host. If the
communications parameters of the host and Meter do not match, set the appropriate baud
rate and parity parameters as follows:
1. Press P to turn the Meter on.
2. Press Q then K. The baud rate currently selected is shown in the primary
2. Press Q then K. The baud rate currently selected is shown in the primary
display and baud is shown in the secondary display.
3. Press U or V to scroll to the desired baud, and then press R to set the
RS-232 baud rate.
4. Press U or V to scroll to the desired data bit (7 or 8) selection, then press
R
to set parity. Echo appears on the secondary display, and 0n or 0FF appears
on the primary display.
5. To select an Echo mode, press U or V to select On or OFF, and then press
R
to set the selected Echo state. When Echo is on, each command sent to the
Meter over the RS-232 interface is echoed to the host's display screen. When
Echo is off, commands are not echoed.