GF Signet 8900 Multi-Parameter Controller - Manual (Page 32)

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) ) >