Table of Contents
Advertisement
5.11
RS 232 interface
5.11.1
Cable and test of the RS 232 interface
Signal
9-pin sub-D socket
With hard-
ware hand-
shake
RxD
2
TxD
3
DTR
4
Signal
5
ground
DSR
6
RTS
7
CTS
8
5.11.2
Protocol RS 232
V3
Computer
25-pin sub-D socket
Without
With hard-
hardware
ware hand-
handshake
shake
2
3
3
2
20
5
7
6
4
5
Take the following information into account:
With hardware handshake: When connecting a thermostat to the PC,
use a 1:1 and not a null modem cable. The RS 232 interface can be con-
nected directly to the PC using a 1:1 contacted cable.
Without hardware handshake: Set the corresponding operation mode on
the PC. Use protected connection lines. Connect the protective screen
with the connector shell. The lines are galvanically separated from the
rest of the electronics. Do not connect unassigned pins.
It is easy to check the RS 232 interface when it is connected to a PC
with a Microsoft Windows operating system.
For Windows
For Windows
For operating systems Windows Vista, Windows 7, and Windows 8 "Hyper-
Terminal" is no longer part of the operating system.
Terminal programs are available on the Internet as freeware. These pro-
grams offer features similar to "HyperTerminal" (for example PuTTY).
Search query "serial port terminal program".
Take the following information into account:
Connection to SUB-D socket 9-pin
The interface works with 1 stop bit, without a parity bit and with 8 data
bits.
Transmission speed alternately: 2400, 4800, 9600 (factory setting) or
19200 bauds.
The RS 232 interface can be operated with AND without hardware
handshake (RTS/CTS). In order to do so, Pin 4 (DSR) and Pin 6 (DTR)
and Pin 7 (CTS) and Pin 8 (RTS) must be connected with a bridge.
LOOP
9-pin sub-D socket
Without
With hard-
hardware
ware hand-
handshake
shake
3
2
2
3
4
7
5
6
7
8
3.11 with the program "Terminal".
®
®
95/98/NT/XP with the program "HyperTerminal".
Thermostat
Signal
Without
hardware
handshake
2
TxD
3
RxD
DSR
5
Signal
ground
DTR
CTS
RTS
29 / 41
Advertisement
Table of Contents
