Spirax Sarco RIM20, Installation And Maintenance Instructions Manual, Page: 40 / 132

IM-P198-05 MI Issue 2 40
3.23 Pulse output connections
The pulse output is used for a remote counter. When the preset volume or mass (defined
in the totalizer settings, see Section 4) has passed the meter, the output provides a 50
millisecond square pulse.
The pulse output optical relay is a normally-open single-pole relay. The relay has a nominal
200 volt/160 ohm rating. This means that it has a nominal on-resistance of 160 ohms, and
the largest voltage that it can withstand across the output terminals is 200 volts. However,
there are current and power specifications that must be observed. The relay can conduct a
current up to 40 mA and can dissipate up to 320 mW. The relay output is isolated from the
meter electronics and power supply.
There are three connection options for the pulse output-the first with a separate power supply
(Figure 34), the second using the flowmeter power supply (Figure 35)(dc powered units only),
and the third using the internal 24 Vdc power supply (Figure 36)(ac powered units only). Use
the first option with a separate power supply (5 to 36 Vdc) if a specific voltage is needed for
the pulse output. Use the second configuration if the voltage at the flowmeter power supply
is an acceptable driver voltage for the load connected. (Take into account that the current
used by the pulse load comesfrom the meter's power supply). Use the third configuration if
you have an ac powered unit only. In any case, the voltage of the pulse output is the same
as the voltage supplied to the circuit.