102
Communication setup
8.5 Analog inputs
8.5.1 Analog inputs connection
Note: 4–20 mA inputs must be isolated. Maximum load per unit is 200 ohms.
Analog voltage as well as analog current input signals are accommodated in a single
connector. To connect the analog voltage signal (–4.0 to +4.0 V dc):
1.
Tie ground wire to Pin B (ground).
2.
Tie analog voltage wire to the appropriate voltage input pin
(Pin C, E, or G).
For example, to connect an analog voltage input to analog input channel 1, tie the ground
wire to pin B and your positive wire to pin C.
To connect and analog current signal (4–20 mA dc)
1.
Tie ground wire to Pin B (ground).
2.
Connect analog current wire to both voltage and current input pins for the appropriate
channel (Pin C and D, or E and F, or G and H).
Figure 33 Deadband concept (low setpoint example)
1
pH values scale
4
Deadband
2
Setpoint trigger On
5
Setpoint (7.00)
3
Setpoint trigger Off
6
Scan intervals
Goodnal STP ST041 Pre Treatment (Sigma 900 MAX All Weather Refrigerated Sampler) Vendor Manual
Q-Pulse Id VM373
Active 29/10/2013
Page 102 of 122
