TECHNICAL INFORMATION
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CN929-7015M002
Treset
Maximum delay between consecutive bytes of the same data packet.
The controller can reinitialize reception if this time frame expires without
data exchange.
2 byte time
2
Tmin
Minimum time frame before a reply can be initiated. The controller’s
reply message cannot begin until the expiry of this time frame, which is
initiated at the end of the Host message.
4 msec
Tmax
Maximum time frame within which a reply can be given. The controller’s
reply message cannot begin until the expiry of this time frame, which is
initiated at the end of the Host message.
100 msec
Tquery
Minimum time frame for query transmission.
nº byte x byte time
Tresponse
Minimum time frame for reply transmission.
nº byte x byte time
Trelease
Maximum time frame within which the RS485 line can be freed. Within
this time frame the controller must free the serial line upon completion of
reply transmission. Such time out is relevant in the RS485 mode only.
2 byte time
2
Equivalent to the transmission time of a single byte at the selected baud rate and assumes the following values:
8.33 msec at 1200, 4.16 msec at 2400, 2.08 msec at 4800, 1.04 msec at 9600.
A data exchange session will therefore assume the timing shown in the following figure:
Timing
Data Exchange Error Management
The following data exchange errors are handled (during
reception by the controller):
Error Type
Possible Cause
Overrun
Problems with the E-Net Dual
Controller’s data exchange driver
Frame error
Line noise, incorrect baud rate or
data corruption
Checksum
error
Data corruption
Full buffer
Too many bytes or data corruption
Bad header
Inexistant or incorrect header
Time-out
Unrespected time out (Treset)
When a data exchange error occurs, the E-Net Dual
Controller does not react in any way to the command
received but replies with an NACK message except in
cases when an RS485 serial line is used.
If an unrecoverable error (crash error) occurs on the
E-Net Dual Controller, the serial line will not be able to
handle any type of data exchange.