Detailed Description Of The Bits (Input Byte 0) - Leuze electronic MA 258i Operating Instructions Manual

10.2.2 Detailed description of the bits (input byte 0)

Bit 0: Write-Acknowledge: W-ACK
This bit is only relevant for writing slave data in blocks, see chapter 11.1.2 (buffer data on
RS 232). It toggles when data from the PLC are sent to the MA with CTB or SFB.
Input data
W-ACK
Bit 2: Service mode active: SMA
Input data
SMA
Bit 3: Data exist: DEX
This bit is only relevant for reading slave data in Collective mode relevant, see chapter 11.1.1.
Input data
DEX
Leuze electronic
Description
Write-Acknowledge
(write confirmation)
Write handshake
Indicates that the data was successfully sent by the PLC to
the gateway.
Write-Acknowledge is indicated via this bit. The W-ACK bit
is toggled by the fieldbus gateway whenever a transmit com-
mand has been successfully executed. This applies both for
the transmission of data to the transmit buffer with the CTB
command and for sending the transmit buffer contents with
the SFB command.
Description
Service mode active (SMA)
The SMA bit is set if the service switch is set to "MA" or
"DEV", i.e. if the device is in either fieldbus gateway or Leuze
device service mode. This is also indicated by a flashing PWR
LED on the front side of the device. Upon changing to the nor-
mal operating mode "RUN", the bit is reset.
Description
Data exist
(data in transmit buffer)
Indicates that further data is stored in the transmit buffer
which is ready for transmission to the control. This flag bit is
always set to high ("1") by the fieldbus gateway as long as
data is in the buffer.
Addr. Data
0.0
Addr. Data
0.2
Addr. Data
0.3
MA 258i
Telegram
Value range
type
0->1: Successfully
written
Bit
1->0: Successfully
written
Value range
type
0: Device in
operating mode
Bit
1: Device in service
mode
Value range
type
0: No data in the
transmit buffer
Bit
1: Further data in
the transmit buffer
Default
0
Default
0h
Default
0h
55