1. INTRODUCTION
The electronic transmitters CP420L and CH420L are designed to work with Tecfluid’s
volumetric counters (COVOL) and turbines. The instruments are supplied already configured
for the type of input.
The circuit is based on a microprocessor that, in function of the pulses per litre programmed,
calculates the flow rate and totalizes the volume that flows through the meter and shows
these values on a local indicator.
The CH420L differs from CP420L in that it is also HART protocol compatible.
2. OPERATION
To adapt the transmitter to the meter, the pulses per litre factor specified on the meter must
be programmed. To do this, the plastic front cover must be removed by unscrewing the four
screws on the corners. After that, the push buttons will be accessible.
If the instrument has not been previously programmed or, due to an alteration in the data
memory the instrument recovers the default factory values, then the display will show
“PRESET”. This indication will disappear when the programming sequence has been
completed.
There are three push buttons with the following functions:
2.1. Programming
In all the programming screens, the “RESET” push button exits the screen without saving
the data in the memory, even if changes in the digits have been made or not .
By pushing the two push buttons PROG at the same time, the display will change to the
programming mode. In this mode there are 7 digits (four whole numbers and three
decimals). The value that must be introduced is the pulses per litre factor given on the
label of the COVOL or Turbine.
To do this, pushing the push button marked with the arrow pointing upwards, the blinking
digit will increase. Once the desired value of the digit is achieved, by pressing the push
button marked with the arrow pointing left, the cursor will pass to the next digit to be
modified. On the seventh digit, by pressing this push-button the cursor will pass to the first
digit on the display.
When the value of the pulses per litre is correct, by pushing the two push buttons PROG
at the same time, this value will be automatically saved in the memory and it will appear the
units selection screen.
2
