Cinterion
®
LTE Terminals Hardware Interface Description
3.5 RS-232 Interface
47
ELSxT_HID_v04
2018-09-04
Confidential / Preliminary
Page 28 of 102
3.5
RS-232 Interface
The interface is implemented as a serial asynchronous transmitter and receiver conforming to
ITU-T V.24 Interchange Circuits DCE. It is configured for 8 data bits, no parity and 1 stop bit,
and can be operated at bit rates from 1200bps to 921kbps. Autobauding supports bit rates from
1.2kbps to 230kbps.
For more information see also
3.5.1
9-Pole D-sub Connector
Via RS-232 interface, the host controller controls the LTE Terminals and transports data.
Figure 7:
Pin assignment RS-232 (D-sub 9-pole female)
LTE Terminals are designed for use as a DCE. Based on the conventions for DCE-DTE con-
nections it communicates with the customer application (DTE) using the following signals:
•
Port TxD @ application sends data to TXD0 of the LTE Terminals
•
Port RxD @ application receives data from RXD0 of the LTE Terminals
Table 13:
9-pole D-sub (female) RS-232
Pin no.
Signal name
I/O
Function
1
DCD0
O
Data Carrier Detected
2
RXD0
O
Receive Data
3
TXD0
I
Transmit Data
4
DTR0
I
Data Terminal Ready
Attention: The ignition of LTE Terminals is activated via a rising
edge of high potential (+3 ... +15 V)
5
GND
-
Ground
6
DSR0
1
1. Note that DSR0 may also be available via GPIO connector pin - see
.
O
Data Set Ready
7
RTS0
I
Request To Send
8
CTS0
O
Clear To Send
9
RING0
O
Ring Indication
1
2
3
4
5
6
7
8
9