3-1
Section
Analog I/O Units
172
CPU Unit, or previous Expansion Unit or Expansion I/O Unit, the allocation will
be as follows:
Analog I/O Unit
(m + 1)
(m + 2)
2 analog inputs
1 analog output
(n + 1)
For example, in the following diagram an Analog I/O Unit is connected to a CPU
Unit with 30 I/O points.
Input address
Output address
30-point CPU
Unit
Analog I/O
Unit
IR 000
IR 001
IR 010
IR 011
IR 002
IR 003
IR 012
Wiring Analog I/O Devices
Analog Input Wiring
2-core shielded
twisted-pair cable
Analog
output
device
voltage
output
Analog
output
device
current
output
Analog I/O Unit
250
Ω
250
Ω
10 k
Ω
10 k
Ω
Analog Output Wiring
Voltage Outputs
2-core shielded
twisted-pair cable
Analog I/O Unit
Analog
input
device
voltage
input
Current Outputs
2-core shielded
twisted-pair cable
Analog I/O Unit
Analog
output
device
current
input