Ercogener GenPro 425e - RS485 Serial Link

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Descriptions and non-contractual illustrations in this document are given as an indication only.
ercogener reserves the right to make any modifications.
Dct_427_02
3.6 RS485 serial link
By default, the GenPro 425e provides a serial link RS485 that can be used with a specific software
application.
Using the RS485 serial link requires the physical disconnection of the signals CT107/DSR
and CT108-2/DTR of the main serial link. See scheme above.
For the connection, see recommendations below.
Table 18 : Pins description of serial link RS485
Signal
Spring cage
connector
Pins N°
I/O
RS485
Standards
Description
A+
1
I/O
A/Y
I/O not inverted
B-
2
I/O
B/Z
I/O inverted
Table 19 : Characteristics of RS485 serial link
Characteristics
Symbols
Conditions
Min.
Typ.
Max.
Unit
Interface voltage (A or B)
V
IO
-1.25
6.1
V
DC
Transmitter
Differential Output Voltage
V
OD
1,5
3
V
DC
Driver Common Mode Output
V
OC
3
V
DC
Short-Circuit Current
I
OSD
–7V ≤ (A or B) ≤ 12V
±200
mA
Receiver
Input Current (A, B)
I
IN
–7V ≤ (V
IN
) ≤ 12V
-100
125
µA
Differential Input Threshold
Voltage
V
TH
0V ≤ B ≤ 6.1V
±0,2
V
DC
Input Hysteresis
ΔV
TH
B = 0V
25
mV
DC
Output High Voltage
V
OH
I
O
= –4mA, A-B = 200mV
2.4
V
DC
Output Low Voltage
V
OL
0,4
V
DC
Termination resistance
Resistor
RT
118.8
120
121.2
ohms