Rockwell Automation 1734-485ASC POINT I/O ASCII User Manual - Manual (Page 46)

Publication 1734-UM009B-EN-P - July 2003
2-20 Configuring Your ASCII Module
Explicit Messages to Receive the Serial Data String
Parameters 14, 15, and 16 contain the status of the most recent
incoming serial data string. You can use the data to read your device’s
ASCII data via the explicit messaging technique.
Parameter 14 holds the most recent received data. Parameter 15
defines the size (in bytes) of the DeviceNet message to be sent by the
ASCII module to the master. Parameter 16 holds the transaction ID of
the data string in Parameter 14 if the Header option is selected.
Status Byte Description
The Serial Status byte is an OR’d bit field of a number of status and
exception flags.
TX Buffer Overflow (Bit 0)
The transmit queue has overflowed resulting in a loss of data. The
transmit I/O is full of data waiting to be transmitted. Some of the data
added has been lost. When space becomes available in the TX, this bit
will be reset.
RX Buffer Overflow (Bit 1)
The receive queue has overflowed resulting in a loss of data. The
receive is full of data waiting to be processed. The data has been lost.
When space becomes available in the RX, this bit will be reset.
IMPORTANT
You must upload this data from the ASCII module to
view current information or put your RSNetWorx for
DeviceNet into Monitor Mode.
Table 2.7 Serial Status Byte
Bit Exception
0 TX Buffer Overflow
1 RX Buffer Overflow
2 RX Parity Error
6 Handshake Error
7 New Data Flag