52
For example:
Maximum fl ow rate = 120 gr/min (120 gr/min = 2 gr/sec)
If unit per pulse is set to 120 gr per pulse, the Pulse Output will pulse once every minute.
If unit per pulse is set to 2 gr per pulse, the Pulse Output will pulse once every second.
The Pulse Output incorporates the pulse output queue, which accumulates pulses if the
Pulse Output is accumulating process fl ow faster than the pulse output hardware can pro-
duce. The queue will allow the pulses to “catch up” later if the fl ow rate decreases. A better
practice is to slow down the Pulse Output by increasing the value in the Unit/Pulse setting in
the Pulse Output menu (see Figure 19).
NOTE: If Pulse Output feature is required, the Solid State Relay (SSR) output
must be assigned to the “Pulse Output” function (see Section 6.4.15.6). The
Pulse output signal will be accessible via SSR output (pins 1 and 2) on the DPC
8-pin MiniDIN connector (see Figure 3 for proper wiring connections).
6.4.15 General Settings
6.4.15.1 Valve Parameters
For information related to Valve Parameters see Section 6.4.3 Instrument Set Point and
Valve Control” on page 25.
6.4.15.2 STP / NPT Conditions
This menu selection allows the user to set desired standard temperature and pressure
conditions or normal temperature and pressure conditions. Following options are available
in this menu selection:
Standard Temperature
Standard Pressure
Normal Temperature
Normal Pressure
Standard Temperature and Normal Temperature menu selections allow the user to fi rst select
desired temperature units of measure: °C, °F, °K, or °R. By default, currently active tem-
perature units will be selected. Once the units are selected, the use can adjust the desired
temperature value and press the joystick equivalent of an ENT button to save it. By default,
currently stored values will be displayed.
NOTE: The Pulse Output minimum Active On time is 50 milliseconds (0.05
second). The Pulse Output cannot operate faster than one pulse every 100
milliseconds (0.1 second). A good rule to follow is to set the Unit/Pulse
value equal to the maximum fl ow in the same units per second. This will
limit the pulse rate to no faster than one pulse every second.
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