Remote Operation; Data Communication; Layout Of Commands; Command Reference - Hameg HM8112-3 Benutzerhandbuch

R e m o t e O p e r a t i o n

12 Remote Operation

The Dual Interface USB/RS-232 HO820 and the GPIB interface
HO880 are electrically isolated from the measuring circuit.
The instrument is programmable by a PC. Functions and ranges
can be selected and measurement values stored in the instru-
ment can be read out. The respective drivers are available on
the enclosed Product CD or can be downloaded at http://www.
hameg.com.
The HM8112-3 is connected to another instrument
by a 1:1 interface cable. It is recommended to use a
9 to 25 pin standard adapter if a PC with a 25 pin
COM port is connected.
Interface parameters RS-232
Settings: No parity bit, 8 data bits, one stop bit, Xon-Xoff
Baudrate: The communication is carried out with 9600 baud.
USB interface
You do not have to change the configuration. If required, the
baud rate can be changed. Connect the HM8112-3 with your PC
using a USB cable and install the USB drivers like described in
the manual of the USB interface HO820.
GPIB interface
It is necessary to change the GPIB adress of the function gene-
rator to the desired value. The adress is changed at the interface
on the back panel. Connect the HM8112-3 with your PC using a
GPIB cable and set the baud rate to 9600 baud.

13 Data communication

13.1 Layout of commands

A command consists of 5 ASCII characters:
1. Character: 0
2. Character: Command category (0, 1, 2 or E)
3. Character: Function between 0 and F
4. Character: Parameter between 0 and F
5. Character: Terminator, either CR or LF
– all commands end with CR or LF
– the character set includes figures 0 – 9, characters A – F
and CR, LF
– the characters can be entered as upper case or lower case
letters
– Figures 2, 3 and 4 received after 0 are interpreted as a
control command. After a command has been transmitted
a delay of at least 35 ms must be observed, then the next
command can be sent.
A transmission of invalid commands is answered with 02D0
–
in case of wrong length of the command or void command
category, with 02D1 for group 1, with 02D2 for group 2 and
with 02DE for group E. This helps debugging the controller
program. The error message is transmitted immediately
after occurrence.
60
Subject to change without notice
Notes concerning some commands:
0000...0004 Measurement of DC voltage, ranges 100 mV to
600 V
0010...0014 True RMS with DC
0016...0019 True RMS without DC
02C3...02C5 This message is sent after a change of function
or range
02F0...02F3 Request of the instrument's data
By pressing button „LOCAL" the instrument re-
turns to manual mode.

13.2 Command reference

Group 0 controls all measurement functions. If a measurement
time > 1s was selected, it will be set to 1 s after any change of
function. A change of range will not affect the measurement time
selected. A change of function or range will, however, always
cause a fresh selection of filters.
Function 0 to 5:
This parameter selects the range, autoranging will be disabled.
Parameter 9 (no change) will retain the previous range selection.
Function 1:
Parameters 0 to 4 select DC coupling, 6 to 9 AC coupling.
Function 8:
FREQ VAC requires a valid parameter 1 or 2. During frequency
measurement the voltage measurement will be disabled, hence
also autoranging. The range previously selected in the function
VAC will be retained.
Function B:
Diode test with parameter 9.
Function C:
Continuity test with parameter 6 (R
Functions D and E:
2- or 4-wire-temperature measurements require parameter
3 for PT100 or 5 for PT1000.
Function F:
Temperature measurement with thermocouple, requires pa-
rameter 1 for type J or 2 for type K.
Group 1 controls the measurement functions of the instru-
ment.
Function 0 (Autorange):
– Parameter 0 turns autoranging off.
– Parameter 1 turns autoranging on.
– Parameter 8 selects the next higher range until the highest
is reached.
– Parameter 9 selects the next lower range until the lowest
is reached.
Function 1 (Meas – Time):
– Parameter 1 to 7 select the measurement time from 10
ms to 60 s. The measurement results are available at the
interface with the measurement time chosen.
– Parameter 8 selects the next higher measurement time
until the longest is reached.
– Parameter 9 selets the next lower measurement time until
the shortest is reached.
= 10 Ω).
threshold