User Manual

32
Signet 8900 Multi-Parameter
10
5
ela utut ate
0 t 00 Pulemin
enint
Pulse rate
0 pulses
100 pulses
Starting int
Proportional Pulsing
• Proportional Pulse mode varies the frequency of pulses in direct
proportion to minimum and maximum setpoints.
• The 8900 does not allow use of this mode for Pressure applications.
Example:
• The output will be 0 pulses/min. at process values less than 5.0.
• The output will be 50 pulses/min. when the process value is 7.5.
• The output will be 100 pulses/min. at process values above 10.
0
20
0
0
80
100
elay Pulse idth as a  of elay period
PM
minimum
range
PM
maximum
range
elay is
always 
elay is
always 
Process value
Pulse Width Modulation
• PWM automatically varies the ratio of ON time to OFF time
proportional to minimum and maximum range settings.
• The relay period is the sum of the time a relay is ON and the
time it is OFF.
• Relay pulse width is the time the relay is ON.
• The 8900 must be programmed with the relay period, and with
the low and high setpoints.
• The 8900 does not allow use of this mode for Pressure
applications.
Example:
• The pulse width will be 0% of the relay period (relay always OFF)
when the process value is less than the minimum range.
• The pulse width will be 100% of the relay period (relay always
ON) when the process value is greater than the maximum range.
• The pulse width will be 60% of the relay period when the process
value is at 60% of the span between the minimum and maximum
range.
Volumetric Pulse
• A pulse is generated each time a specifi ed volume of fl uid is
registered. For fl ow inputs only.
Totalizer Volume
• Relay activates and latches when a specifi ed volume of fl uid
is registered. For fl ow inputs only.
• Total Volume mode counts the TOTALIZER Units until the
setpoint volume is reached, then activates the relay until the
resettable totalizer is reset.
• If the Resettable Totalizer reading is greater than the
setpoint, the relay will be activated immediately. The relay
will be relaxed when the totalizer is reset to zero.
• This mode is useful to trigger a reminder when a process is
due, as for a backwash cycle or fi lter change.
Advanced
• Relay is activated when a set of three conditions (a, b and c)
are met. See detailed explanation in Section 11.2.
Relay 1 Operator:
( a &(b | c) ) >