Hach EC1000 Instruction Manual page 76

Figure 22 RS-232C Interface Configuration
1 2 3 4 5 6 7
TB1
Host Computer
25 CKT D-Subminiature Female
Connection
PIN 1 (SHLD) Note 1
TB1-2 (TXD)
PIN 3 (RXD)
PIN 2 (TXD)
TB1-3 (RXD)
TB1-1 (COM) PIN 7 (COM)
PIN 4 (RTS) to PIN 5 (CTS)
PIN 6 (DSR) to PIN 20 (DTR)
PINS 8-19, 21-25 NOT USED
Note 1: Shield ground is normally tied at one end of
cable only to prevent ground looping.
1 2 3 4 5 6 7
TB1
Host Computer
9 CKT D-Subminiature Female
Connection
TB1-2 (TXD)
PIN 2 (RXD)
TB1-3 (RXD) PIN 3 (TXD)
TB1-1 (COM)
PIN (COM)
PIN 7 (RTS) to PIN 8 (CTS)
PIN 6 (DSR) to PIN 4 (DTR)
PINS 1, 9 Not Used
1 2 3 4 5 6 7
TB1
Citizen Printer
Connection 25 CKT D-Subminiature Male
PIN 1 (SHLD) Note 1
TB1-2 (TXD)
PIN 3 (RXD)
TB1-1 (COM) PIN 7 (COM)
Note 1: Shield ground is normally tied at one end of
cable only to prevent ground looping.
13
13
25
76
25
Host Computer
25 CKT D-Subminiature Female
5
9
6
Host Computer
9 CKT D-Subminiature Female
Citizen Printer Connection
25 CKT D-Subminiature Male
1
14
1
14