Yokogawa 415 Steam and Gas - Manual (Page 45)

4.2 THE RS232/422/485 INTERFACE OPTION
With this option installed, the circuits for both the RS232 and RS422/485 are
provided as standard. They can be used to interface to both printers and
computers, and a number of standard protocols are built into the instrument.
4.2.1 Hardware
The following diagram provides an overview of the RS232/RS422/RS485
communications hardware. All three interfaces are available on the rear terminal
strips and the user can select either one by making the appropriate connections.
The RS232 interface is primarily used with printers or for simple communication
with a computer over a short distance. The RS422 and RS485 interfaces are used
for communication over a long distance or in applications requiring multipoint
communication.
Options 43
24
23
26
25
21
22
20
( + )
(-)
( + )
(-)
RS422 Out
RS422 In
Data In
Data Out
Ground
RS232
27 CTS