H72.0.11.6C-04
Operating Manual GMH 3451
page 13 of 18
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9 Universal
output
The output can be used as serial interface (for USB 3100, USB 3100 N, GRS 3100 or GRS 3105
interface adapters) or as analogue output (0-1V).
If none of both is needed, we suggest to switch the output off, because battery life then is extended.
When operating with external supply or connected interface and measurement at solutions
with earth connection, there may appear distortions or deviations of the measuring. In case of
doubt disconnect supply/interface.
The same is valid for the analogue output: Depending how the output is connected (e.g. even
without isolation), in case of doubt do not measure in solutions with earth contact.
9.1 Serial Interface
By means of the serial interface and a suitable electrically isolated interface adapter (USB 3100, USB 3100
N, GRS 3100 or GRS 3105) the device can be connected to a computer for data transfer.
With the GRS 3105 up to 5 devices of the GMH3xxx- series can be connected to one interface (see also
manual of GRS 3105). As a precondition the base addresses of all devices must not be identical, make sure
to configure the base addresses accordingly (refer menu point “Adr.” in chapter 1 “Configuration“).
To avoid transmission errors, there are several security checks implemented e.g. CRC.
The following standard software packages are available:
GSOFT3050
:
Operation and read out of logger function for devices with integrated data logger
GMHKonfig
:
Software for a comfortable editing of the device (e.g. Material selection…)
EBS 20M / 60M
: 20-/60-channel software to display the measuring values
In case you want to develop your own software we offer a
GMH3000-development package
including:
A universally applicable Windows functions library ('GMH3000.DLL') with documentation that can be
used by the most programming languages. Suitable for Windows XP™, Windows Vista™, Windows 7™,
Windows 8 / 8.1™, Windows 10™
Programming examples Visual Studio 2010 (C#, C++ und VB), Testpoint™,LabView™ uvm.
In addition to the operation at a PC the device can be operated with the
GAM 3000
device, to use the alarm
function for simple supervision and controlling applications. Just connect a GAM 3000 to the interface,
activate the alarm function of the GMH and the relays output is operating.
The device has 2 channels:
- Channel 1: current measuring value Cond, rES, TDS oder SAL (base address)
- Channel 2: temperature value
Supported functions:
1 2 Code Name/Function
1 2 Code Name/Function
x x 0
Read measurement value
x x 200 Read min display range
x x 3
Read system state
x x 201 Read max display range
x 12
Read ID number
x x 202
Read display range - unit
x x 22
Read min alarm rail (AL. - AL.Lo)
x x 204
Read display range - decimal point
x x 23
Read max alarm rail (AL. - AL.Hi)
x 208
Read # of channels
x x 176 Read min measuring range
x 222 Read power off time (Conf-P.oFF)
x x 177 Read max measuring range
x 223 Set power off time (Conf-P.oFF)
x x 178 Read measuring range unit
x 233 Read real time clock (CLOC)
x x 179 Read measuring range decimal point
x 234 Set real time clock (CLOC)
x x 180 Read kind of measuring of sensor
x 240 Reset
x x 199 Read kind of measuring of display
x 254 Program version
The measuring-/ alarm- and display range values read back from the interface are
always in the selected measurement unit!
When using the interface, the auto-range-function should be turned off. If auto-range is
activated, the returned value ar based on the resolution of the smallest ranges, there
may be returned extreme values like 123400.0 µS/cm instead 123.4 mS/cm.
