Leuze electronic GmbH + Co. KG
MA 238
i
38
Bit 5: Data Loss: DL
This bit is important for monitoring data transmission in Transparent and Collective mode.
Bit 6: Buffer Overflow: BO
Bit 7: New Data: ND
This bit is only relevant in Transparent mode.
10.2.3 Detailed description of the bits (input byte 1)
Bit 0 … 7: Data Length Code: DLC0 … DLC7
Input data
Description
Addr.
Data
type
Value range
Default
BLR
Next block ready to transmit
(new block ready)
The Block Ready toggle bit changes its state whenever
the fieldbus gateway has removed received data from
the receive buffer and registered it in the corresponding
receive-data bytes. This signals to the master that the
quantity of data indicated in the DLC bits to be present
in the input data bytes originated in the data buffer and
is current.
0.4
Bit
0->1: Data transmitted
1->0: Data transmitted 0
Input data
Description
Addr.
Data
type
Value range
Default
DL
Data Loss
(data transmission monitoring)
This bit is set until the device is reset (bit pattern see
chapter 10.4 "RESET function / deleting memory") in
case gateway data was not able to be sent to the PLC
and was lost. Furthermore, this bit is set in case the con
-
figured data frame, e.g. 8 bit, should be smaller than the
data to be transmitted to the PLC, e.g. bar code with 20
digits. In this case, the first 8 digits are transmitted to the
PLC, the rest are truncated and are lost. In this process,
the Data loss bit is also set.
0.6
Bit
0->1:
Data Loss
0
Input data
Description
Addr.
Data
type
Value range
Default
BO
Buffer Overflow
(buffer overflow)
This flag bit is set to high ("1") when the buffer overflows.
The bit is automatically reset when the buffer again has
memory space available. While the BO bit is set, the RTS
signal of the serial interface is deactivated.
The memory size of the gateway for the data of both the
PLC and the Leuze end device is 1 kByte.
0.6
Bit
0->1: Buffer overflow
1->0:
Buffer o.k.
0
Input data
Description
Addr.
Data
type
Value range
Default
ND
New Data
(new data)
This bit is toggled on each data set that is sent from the
gateway to the PLC. This can be used to differentiate
between multiple, identical data sets that are sent to the
PLC.
0.7
Bit
0->1; 1->0:
On each status change
for new data
0
Input data
Description
Addr.
Data
type
Value range
Default
DLC0 … DLC7
Data Length Code
(number of user data in bytes)
Stored in these bits is the number of user data bytes
transmitted to the PLC which follow.
1.0 …
1.7
Bit
1
h
(00001
b
) …
FF
h
(00255
b
)
0h
(00000b)
