Heinrichs Messtechnik GmbH
OPERATING MANUAL TMU-W / UMC4
Page 29 of 118
Communication via Siemens PDM
®
PDM
®
is the configuration software of Siemens that is used to operate HART
®
or Profibus PA compatible
devices.
To connect a desktop or laptop computer to the UMC4, a HART
®
interface is required in addition to
communication software such as PDM. The HART
®
interface, which has two connections, converts the levels
of the RS 232 interface or USB interface into an FSK signal (frequency-shift keying).
For further details see section 3.4.10, “Connection to the transmitter” on page 19
4.8.2.4
Damping
The damping of the output signals is programmable from 1 to 60 seconds.
The standard factory setting is 3 seconds.
4.8.2.5
Error indication
An error in, or failure of the meter can be indicated via the current outputs or the status output. The current
outputs can be set to a failure signal (alarm) of I < 3.8 mA or I > 22 mA. The status output can be configured
as a make or break contact.
4.8.2.6
Low flow cut-off
The low flow cut-off can be set to values between 0 and 20% via the menu. The set value is a percentual
value of the upper-range setting. If the measured value is lower than the set cut-off, the flow rate will be
set to 0.0 (kg/h). This results in the analogue output being set to 0/4 mA, and the pulse output will cease
generating pulses.
Binary Outputs
The binary outputs utilise NPN transistors for the transmission of their data. To collect this data (e.g.
Pulses), the connection of an external circuitry is necessary. Image 3 depicts an example of such a circuit.
For use in EX atmospheres, refer to the EX-supplement manual for additional connection requirements.
Image 3: Example for wiring a Binary output
