3
1.5 Wiring instructions
User terminal wiring requirements, as shown in Figure 1-5.
Figure 1-5 Diagram of user terminal wiring
The diagrams
①
to
⑦
indicate the seven aspects that must be taken into account when wiring.
1. It is recommended that the analogue input is connected via a twisted shielded cable. The cable should be routed away
from power cables or other wires that may cause electrical interference.
2. If there are fluctuations in the input signal, or if there is electrical interference in the external wiring, it is recommended to
connect a smoothing capacitor (0.1μF to 0.47μF/25V).
3. If the current channel uses the current input, short the voltage input and the current input for that channel.
4. If there is excessive electrical interference, connect the shielding ground FG to the module earth terminal PG.
5. Ground the module's earth terminal PG well.
6. The analogue power supply can use the 24 Vdc power supply from the main module output, or any other power supply
that meets the requirements.
7. Do not use the empty pins on the user terminals.
2 Instructions for use
2.1 Power indicators
Table 2-1 Power supply indicators
Projects
Description
Analog circuits
24Vdc (-10% to +10%), maximum allowable ripple voltage 2%, 50mA (from mains module or external power supply)
Digital Circuits
5Vdc, 70mA (from the main module)
⑦
⑤
CH1
⑥
DC/DC
Converter
+5V
AGND
-5V
P
G
N
D
VC-4AD
24
V
dc
±
1
0
%
60
mA
FG
AGND
④
AGND
Current signals
CH4
AGND
250
390K
AGND
Voltage signals
①
②
②
③
①
390K
130K
130K
24V-
24V+
130K
130K
390K
390K
250
V4+
I4+
VI4-
FG
V1+
I1+
VI1-
