User's Manual

Radio/Serial Telemetry Module User Manual
Page 18 © March 2000
digital/pulse input DI 1 has a maximum rate of 1000 Hz (min. off time 0.5 ms), while DI 2-4 have a
maximum rate of 100 Hz (min. off time 5 ms). When using DI 1 at high pulse rates (more than 100
Hz), a divide by 10 function may be configured to reduce the pulse count at the output, as Pulse
Outputs have a maximum rate of 100 Hz.
For each pulse input, both the pulse rate and the pulse count are available for mapping to a remote
output. The pulse rate may appear at any analogue output on the remote unit, while the pulse count
can appear at a Pulse Output. The default update time for pulse counts is 1 minute. This can be
changed by changing the update time configuration - refer Chapter 4 Configuration for further
details. The pulse count is a 16 bit value - “roll over” of the count when it exceeds the maximum
value is automatically handled by the modules.
Pulse inputs should be wired in the same way as digital inputs (see Section 2.4.1).
2.4.8 Pulse Output (-1)
A single FET output to common rated at 30VDC, 500 mA is provide for the pulse output "PO".
This output accurately recreates the pulses counted at a pulse input at a -1 or -2 module.
Although the count is accurately re-created, the rate of output pulses may not accurately reflect the
input rate. The actual input pulse rate may be configured to appear at an analogue output if
required. Note that the pulse rate and accumulated value will remain accurate even if a period of
communications failure has occurred. The maximum output rate is 100 Hz. If a high speed pulse
input is used (more than 100 Hz) on PI1 of a -2 module, the pulse input count should not be
transmitted to a PO on the -1 or DO on the -3 without configuring the divide-by-10 function (on the
-2 module)
2.4.9 Pulse Output (-3)
The first four digital outputs on the -3 module may also be used as pulse outputs. The outputs are
FET output to common rated at 30VDC, 500 mA. The outputs will provide a pulse signal of up to
100 Hz. The outputs accurately recreate the pulses counted at pulse inputs at a -1 or -2 module.
Although the count is accurately re-created, the rate of output pulses may not accurately reflect the
input rate. The actual input pulse rate may be configured to appear at an analogue output if
required. Note that the pulse rate and accumulated value will remain accurate even if a period of
communications failure has occurred.
2.4.10 RS232 Serial Port
The serial port is a 9 pin DB9 female and provides for connection to a terminal or to a PC for
configuration, field testing and for factory testing. This port is internally shared with the RS485 -