Data Exchange Mode; Table 21: Status Byte S1; Table 22: Process Data In Data Exchange Mode - WAGO 750-652 Manual

WAGO-I/O-SYSTEM 750
750-652 Serial Interface RS-232 / RS-485

Table 21: Status Byte S1

Bit 7
EOV
IL3
IL4
IL5
BUF_E
CTS
EPR
EFR
EOV
1)
Only applies to flow control "RTS with lead/follow-on time":
Status of the CTS input:
Bit 4 is 0: CTS active
Bit 4 is 1: CTS inactive
For evaluation of the bits of the status byte that signal errors, see chapter
"Diagnostics".
4.2

Data Exchange Mode

The data to be sent and received will be stored in up to 47 input and output bytes
(D0 ... D46). Data flow is controlled with control and status bytes C0 and S0.

Table 22: Process Data in Data Exchange Mode

Process
Image
Length
8 bytes
24 bytes D7
48 bytes D23 Data byte 23
The structure of the control and status bytes is described in the tables below.
Manual
Version 1.4.0
Bit 6 Bit 5
EFR EPR
Input length (number of characters received that are available in the input data,
bit 3)
Input length (number of characters received that are available in the input data,
bit 4)
Input length (number of characters received that are available in the input data,
bit 5)
Buffer empty (message: transmit inactive)
This value is always 0
Error parity (message: error during the parity check)
Error framing (message: data frame is defective)
Error overrun (message: a character was lost during receipt)
Input Data
S0 Status byte 0
D0 Data byte 0
D1 Data byte 1
D2 Data byte 2
...
D6 Data byte 6
Data byte 7
...
D22 Data byte 22
...
D46 Data byte 46
Bit 4 Bit 3
CTS BUF_E
1)
.
Output Data
C0 Control byte 0
D0 Data byte 0
D1 Data byte 1
D2 Data byte 2
...
D6 Data byte 6
D7 Data byte 7
...
D22 Data byte 22
D23 Data byte 23
...
D46 Data byte 46
Process Image
Bit 2 Bit 1
IL5 IL4
31
Bit 0
IL3