64
Communications Setup
8.2.3.4 Choosing the Dial Method (Tone or Pulse)
Press the
CHANGE CHOICE
soft key until the correct dial method (pulse/tone) appears in
the center of the display. Press the
ACCEPT
soft key to continue.
8.3 Analog Communications
Channels 1 through 7 are analog input channels that can accept a signal from an external
device. This signal may range from -4 V dc (min.) to +4 V dc (max.) or from 0 to 20 mA dc
depending on the input selected. In some cases, input signals from certain devices may
also fall somewhere within those ranges. For that reason, each analog input channel
must be mapped to the minimum and maximum signal limits of the external device.
8.3.1 4–20 mA Output
8.3.1.1 4–20 mA Connections
Note:
Due to the power demand of current loops, this option requires that an ac power supply be
installed on the flow meter. Battery power is not sufficient to support the
4–20 mA current loop power requirements.
The 4–20 mA option is available as one or two current-loop interfaces for controlling
external devices such as a chlorinator or a chart recorder. Either one or both of the 4–20
mA outputs can be factory installed and are isolated from each other.
Isolation Voltage Rating
Note:
950 flow meters are available with one or two 4–20 mA outputs. Both outputs are installed in
one receptacle.
•
Between flow meter and either 4–20 mA output: 2500 V ac
•
Between the two 4–20 mA outputs: 1500 V ac
•
Maximum Resistive Load: 600 ohms
•
Output Voltage: 24 V dc, no load
Cable Required:
4–20 mA Output Cable Assembly, 25 ft (7.6 m), 4-pin connector on one end, tinned wire
leads on the other end (P/N 2924).
11:00 AM 21 - APR - 01
MODEM SETUP
ACCEPT
CHANGE
CHOICE
DIAL METHOD
CANCEL
TONE
CHOICES: TONE, PULSE
Table 25 4–20 mA Connector Pin Assignments
Pin
Signal Description
Wire Color
A
output A + (pos)
yellow
B
output A - (neg)
black
C
output B + (pos)
red
D
output B - (neg)
green
Содержание Sigma 950
Страница 2: ......
Страница 6: ...4...
Страница 20: ...18 Introduction...
Страница 34: ...32 Basic Programming Setup...
Страница 50: ...48 Sensor Installation...
Страница 82: ...80 Maintenance...
Страница 83: ...81 Appendix A Program Flow Charts Figure 22 Overview of Basic Program Menus...
Страница 84: ...82 Program Flow Charts Figure 23 Setup Flow Chart...
Страница 85: ...83 Program Flow Charts Figure 24 Options Flow Chart...
Страница 86: ...84 Program Flow Charts Figure 25 Alarms Menus Flow Chart...
Страница 87: ...85 Program Flow Charts Figure 26 Calibration Menus Flow Chart Page 1...
Страница 88: ...86 Program Flow Charts...
Страница 102: ...100 Programming Features...
Страница 106: ...104 Primary Devices Head Measurement Locations...
Страница 126: ...124 SCADA Modbus System Guidelines...