App index, Handshaking, Off-off – Yokogawa Removable Chassis DX1000N User Manual
Page 99
2-5
IM 04L41B01-17E
Using the Serial Interface
1
2
3
4
5
6
App
Index
• Connection example
SD
RD
RS
CS
SG
SD
RD
RS
SG
• OFF-OFF/XON-XON
PC
DX
SD
RD
RS
CS
SG
SD
RD
RS
SG
• XON-RS(XON-RTS)
PC
DX
SD
RD
RS
CS
SG
SD
RD
RS
SG
• CS-RS(CTS-RTS)
PC
DX
CS
CS
CS
2
3
8
7
5
2
3
8
7
5
2
3
8
7
5
The connection of RS on the PC and CS
on the DX is not necessary. However, we
recommend that you wire them so that the
cable can be used in either direction.
Handshaking
When using the RS-232 interface for transferring data, it is necessary for equipment
on both sides to agree on a set of rules to ensure the proper transfer of data. The set
of rules is called handshaking. Because there are various handshaking methods that
can be used between the DX and the PC, you must make sure that the same method is
chosen by both the DX and the PC.
You can choose any of the four methods on the DX in the table below.
Data transmission control
(Control used when sending data to a computer)
Data Reception Control
(Control used when receiving data from a computer)
Software
Handshaking
Software
Handshaking
Table of Handshaking Methods (Yes indicates that it is supported)
OFF-OFF
XON-XON
XON-RS
CS-RS
Handshaking
Stops transmission
when X-OFF is
received. Resume
when X-ON is
received.
Stops sending
when CS (CTS)
is false.
Resumes
when it is true.
No
handshaking
No
handshaking
Sends X-OFF
when the receive
data buffer is 3/4
full. Sends X-ON
when the receive
data buffer is
1/4th full.
Sets RS (RTS) to
False when the
receive data buffer
is 3/4 full. Sets RS
(RTS) to True when
the receive data buffer
becomes 1/4 full.
Hardware
Handshaking
Hardware
Handshaking
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
• OFF-OFF
• Data transmission control
There is no handshaking between the DX and the PC. The “X-OFF” and “X-ON”
signals received from the PC are treated as data, and the CS signal is ignored.
• Data reception control
There is no handshaking between the DX and the PC. When the received buffer
becomes full, all of the data that overflows are discarded.
RS = True (fixed).
2.3 Connecting the DX