Figure 27
Example for programming of proportional control for pH measuring channel.
4.14 Analogical output
4.14.1 Programming as a register
Relay lag. The activation and deactivation of the relays is produced with fixed lag of 2
seconds after reaching the selected limit value.
Important notes:
The minimum effective time of relay activation is 20% of the cycle time. It means that
•
for a cycle time of 10 s despite that the activation time (tON) is 0.5 s, the relay will be
activated during 2 s.
Too short cycle times provoke problems with the induction motors. The electrovalves
•
and membrane pumps respond correctly to this control and do not present this type of
problem.
4
5
MultiMeter 44 has 2 analogical outputs per measuring channels. These outputs can be
used as a register or for control (for regulation).
The programming of the analogical outputs is carried out in the corresponding channel.
One can be used for the measured parameter and the other for the temperature.
The analogical output provides 3 different current levels:
4 to 20 mA for the measured signal.
•
Fixed at 21 mA or last measured value, when the instrument is in Hold.
•
Fixed 22 mA, when alarm relay is activated.
•
1. From the main menu select
2. Select the channel to program and confirm.
3. Select
4-20 MA OUTPUT > REGISTER
4. Enter the 4 mA and 20 mA values using the keypad.
5. Select
to accept the data.
CONTINUE
6
7
8
6.5
7.5
SYSTEM > PROGRAM CHANNEL
and confirm.
9
pH
. Confirm.
Operation
51