MC55i Terminal Hardware Interface Description
4.4 Electrical Specifications of the Application Interface
41
MC55i_Terminal_HD_v01.201a
Page 37 of 47
2010-04-16
Confidential / Released
4.4.2
RS-232 Interface
Table 18:
RS-232 interface specifications (requirements)
Parameter
Description
Conditions
Min.
Typ
Max.
Unit
V
OUT
Transmitter output volt-
age for
/RXD, /CTS, /DSR, /
DCD, /RING
@ 3kOhm load
±5
±6
±7
V
R
OUT
Transmitter output
resistance
/RXD, /CTS, /DSR, /
DCD, /RING
300
Ohm
R
IN
Resistance
/TXD, /RTS, /DTR
3
5
7
kOhm
V
In
Receiver input voltage
range
/TXD, /RTS, /DTR
-15
+15
V
V
RIHYS
Input hysteresis
0.2
0.5
1
V
V
Ilow
Input threshold low
0.8
1.2
V
V
Ihigh
Input threshold high
1.7
2.8
V
Baudrate
Autobauding
1.2
115
kbps
Fixed range
0.300
115
kbps
LE
Cable
Length of RS-232 cable
1.8
2
m
