Specifications

Transmitter M300 FLOW 53

Printed in Switzerland 52 121 319

10.4 Mode

(PATH: Menu/PID Setup/Mode)

This menu contains the selection of control modes using a relay or analog output.

10.4.1 PID Mode

This menu assigns a relay or analog output for PID control action as well as details of their

operation. Based on the control device being used, select one of the following three paragraphs

for use with solenoid valve, pulse input metering pump or analog control.

Pulse Length – If using a solenoid valve, select ”Relays” and ”PL”, Pulse Length. Choose the

ﬁrst relay position as #1 if controlling a pump or signal-to-open valve. Choose the second relay

position as #2 if controlling a signal-to-close valve. Set the pulse length (feed cycle time) in

seconds. A short pulse length will provide more uniform feed. A longer pulse length will reduce

wear on the solenoid valve. A value of 10 seconds may be a good starting point. The % ”on”

time in the cycle is proportional to the control output.

Pulse Frequency – If using a pulse input metering pump, select ”Relays” and ”PF”, Pulse

Frequency. Choose the ﬁrst relay position as #3 if controlling a pump. Choose the second relay

position as #4 if controlling a reverse acting pump. Set the pulse frequency to the maximum

frequency allowed for the particular pump being used, typically 60 to 100 pulses/minute.

Control action will produce this frequency at 100% output.

CAUTION: Setting the Pulse Frequency too high may cause the pump to overheat.

Analog – If using Analog control, change ”Relays” to ”Analogout”. Choose the ﬁrst Analogout

position as #1 if controlling a pump or signal-to-open valve. Choose the second Analogout

position as #2 if controlling a signal-to-close valve. Select the analog output current range

required by the control device, 4–20 or 0–20 mA.

After assigning the PID control action, pressing the [ENTER] key again will bring up the Save

Changes dialog.