Aalborg TIO Totalizer I/O Flow Monitor/Controller Manuel d'utilisateur télécharger pdf (Page 36)

5.3.9 Submenu “Pulse Output”

The flow Pulse Output is operates independently from Totalizers and is based on

configuration settings (see Figure 5.7) which can provide pulse frequency pro-

portional to instantaneous fluid flow rate.

The LCD/keypad and digital communication interface commands are provided to:

• Enable/Disable Pulse Output

• Start Pulse Output at preset flow rate (0.0 – 100.0 %F.S.)

• Configure the Unit/Pulse value (in current engineering units)

• Configure Pulse Active On Time (10 - 6553 ms)

For example: Maximum flow rate = 1200 kg/min

(1200 kg/min = 20 kg/sec)

If unit per pulse is set to 1200 kg per pulse, the Optical Pulse

Output will pulse once every minute.

If unit per pulse is set to 20 kg per pulse, the Optical Pulse Output will pulse

once every second.

The Optically-isolated Pulse Output incorporates Pulse output queue, which accu-

mulates pulses if the Pulse Output is accumulating process flow faster than the

pulse output hardware can function. The queue will allow the pulses to “catch up”

later if the flow 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 5.7).

NOTE: The Pulse Output minimum Active On time is a 10

milliseconds (.01 second). The Optical Pulse Output cannot operate

faster than one pulse every 100 millisecond (.1 second). A good rule

to follow is to set the Unit/Pulse value equal to the maximum flow in

the same units per second. This will limit the pulse rate to no faster

than one pulse every second.

NOTE: If Pulse Output feature is required, one of the Digital Optically-

Isolated outputs must be assigned to the “Pulse Output” function

(see Paragraph 4.3.10). Pulse output signal will be accessible via

corresponding Digital Optically-Isolated output on the screw terminal

header J1 (see Paragraph 3.5 for proper wiring connections).

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Aalborg TIO Totalizer I/O Flow Monitor/Controller Manuel d'utilisateur Page 36