Siemens SIMATIC TIWAY 1 User Manual page 80

Table 4–3 RS–232–C/RS–423–A "D" Connector Pin Assignment
The line drivers and receivers meet the requirements for the RS–423–A and
RS–232–C standards. The modem interface is user–selected for either
asynchronous or synchronous operation at data rates of 110, 150, 300, 600,
1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K, and 115.2K bits per second.
Modem interface circuits can be longer than the 25,000 feet limit of the Local
Line interface. This interface must be used for cross-building or cross-town
circuits. The modems used must be non-intelligent and have data transparency.
Non-intelligent refers to the class of modems that do not have an internal
command set. Modems such as the Hayes Smartmodem
have an internal command set and should not be used. Generally, modems that
meet the Bell 103, 202, and 208 specifications will work, but the Bell 212A class
modems will not. In addition to being non-intelligent, the modems must support
data transparency which means no start bits, no stop bits, and no parity. This is
necessary because TIWAY I uses the bit-oriented HDLC protocol to transfer
information between devices. Most short haul modems are non–intelligent and
provide data transparency.
UNILINK HOST ADAPTER
USER MANUAL
THE TIWAY I NETWORK PORTS
Interchange Connector
Circuit Pin No.
AA 1
AB 7
BA 2
BB 3
CA 4
CB 5
CC 6
CD 20
CF 8
DB 15
DD 17
CCITT Description
101 Protective Ground
102 Signal Ground
103 Transmitted Data
104 Receive Data
105 Request To Send
106 Clear To Send
107 Data Set Ready
108/2 Data Terminal Ready
109 Recieve Line Signal
Detector
114 Transmitter Signal
Element Timing
115 Reciever Signal
Element Timing
4-6
and compatibles do