Jetter JC-120MC, Руководство пользователя

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466 Jetter AG
10 Programming
Number Part Function
9
Status and control
register
Query of filling levels and error states of buffers;
setting of transmission parameters
A character is received as described below:
Step Description
1 The interface driver converts signals "on the line" into internal signal levels
and forwards them to the receiver.
2 The receiver performs serial/parallel conversion of this character and
checks the set communication parameters.
3 The receiver enters the character into the receive buffer if there is any
place left. Otherwise, the character is discarded and buffer overflow is
signaled.
4 Via receive register the character can be read out of the receive buffer.
A character is transmitted as described below:
Step Description
1
Via transmit register the character is entered into the transmit buffer if
there is any place left. Otherwise the character is discarded.
2
Once the transmitter has sent a character, it reads the next character from
the transmit buffer.
3
The transmitter performs parallel/serial conversion and sends this
character to the interface driver using the set communication parameters.
4 The interface driver converts internal signal levels into the various
interface standards.
When receiving characters, the following errors are detected by the controller
and displayed in the register Error state :
Error Description Effect
Framing error The format of the received
character does not match the
set parameters.
The erroneous character(s) is (are)
stored in the receive buffer and
error bit Framing error is set. The
error counter is incremented.
Parity error The parity bit of the received
character is not correct.
The erroneous character is stored
in the receive buffer and error bit
Parity error is set. The error
counter is incremented.
Buffer overflow A character is received,
although the receive buffer is
full.
The character is discarded and
error bit Overflow is set. The error
counter is incremented.
As error bits cannot be assigned to individual characters in the receive buffer,
Receiving a character
Sending a character
Error detection
Troubleshooting