SATEC ETC2002 - Manual (Page 9)

Chapter 2 Installation Electrical Installation
ETC2002 Network Communicator 9
COM3 RS-232 Connection
Figure 2-7 Simple RS-232 3-Wire Connection, 9-pin Female Connector
Figure 2-8 Simple RS-232 3-Wire Connection, 25-pin Connector
COM4/COM5 RS-422/RS-485 Connection
Figure 2-9 Multidrop RS-422 Connection