FLOWPULSE INSTRUCTION MANUAL
16
Terminal Connections
Power
FlowPulse operates from DC power supply or batteries within the range of
18 to 28 VDC. When using a long cable (in excess of 100 m), please ensure
that the minimum supply voltage is at least 22 VDC for the Relay to operate
reliably.
Relay Outputs
The relay can be programmed for a variety of alarms. The relay contacts on
the FlowPulse are rated at 1A at 24V DC. All connections should be such
that the short circuit capacity of the circuits to which they are connected, is
limited by fuses rated so that they do not exceed the relay rating.
The N.O. terminal is normally open while the N.C. terminal is a normally
closed circuit to the common terminal.
Current Output
There is one mA output, of 4 - 20mA with a maximum load of 1k*. It has a 20
µA resolution and a user programmable and adjustable span.
RS232 Serial Interface
The RS232 interface is available on the RJ-11 socket for setting up and
operating the FlowPulse using the FlowPulse PC software. It is
recommended that the serial cable does not exceed 10 metres in length.
RS485 Serial Interface with Modbus
It is recommended that a screened cable is used, and the cable screen is
connected to the screen terminal of the RS485 terminals. If RS485
connection is not required, the cable screen should be connected to the
metal enclosure of FlowPulse at the cable entry point and earthed at the
other end of the cable. The RS485 terminals are galvanically isolated.
Please ensure that the termination switch is set to the “ON” position if
termination is required.
The RS485 serial port can either be used with the Modbus RTU protocol or
to interface with FlowPulse PC.
