MagTek MCP - Manual (Page 27)

Section 3. Transport Frame Types
21
Description:
The frame resend indication is used to notify a node that one of its frames was received with data
errors. The node may either ignore this indication or resend the specified frame. The frame
resend command is an indication. It does not require a response from the recipient. If a node
decides to respond to the indication, it must resend the frame identified by the PCB in the
indication. The error type is provided only for diagnostic purposes. It does not affect the
protocol. The use of the command is optional. The command’s sole purpose is to speed up error
recovery.
Data:
The data field for the indication is defined as follows:
PCB ETYP
• PCB
PCB field of the failed frame
• ETYP
type of error detected (incorrect EDC, line error, etc.).
The error type can be one of the following:
ETYP Definition
0 RFU
1
EDC or Parity Error
2 Character Wait Timeout Error
3-255 RFU