Registers - Description - Jetter JVM-104-O15 User Manual

Jetter AG
Troubleshooting

7.4.2 Registers - Description

JVM-104-O15 User Manual
Errors Description
Parity error The parity bit of the received
character is not correct.
Buffer overflow A character is received, al-
though the receive buffer is
full.
As error bits cannot be assigned to individual characters in the receive buffer, all
characters should be removed from the receive buffer and discarded when an er-
ror bit is set.
Possible causes of error and troubleshooting:
Errors Possible cause
Framing error Jammed data transmission
caused by EMC problems,
defective cables or connec-
tors
Incorrectly set communica-
tion parameters (baud rate,
number of stop bits, etc.)
Parity error Jammed data transmission
caused by EMC problems,
defective cables or connec-
tors
Incorrectly set parity
Buffer overflow The external device sends
characters at too high a rate
and the application program
is not able to read them out
of the receive buffer in due
time.
This chapter describes the registers associated with the user-programmable se-
rial interface. These registers are used for the following tasks:
■ Parameterizing the interface
■ Sending characters
■ Receiving characters
Programming | 7
Effect
The erroneous character is
stored in the receive buffer
and error bit Parity error is set.
The error counter is incre-
mented.
The character is discarded and
error bit Overflow is set. The
error counter is incremented.
Troubleshooting
■ Check the wiring and con-
nectors.
■ Use shielded cables.
■ Do not lay cables near
sources of interference.
■ Make sure the set communi-
cation parameters are con-
sistent with the settings of
the connected device.
■ Check the wiring and con-
nectors.
■ Use shielded cables.
■ Do not lay cables near
sources of interference.
■ Make sure the parity setting
is consistent with the setting
of the connected device.
■ Program a software hand-
shake.
■ Set a lower baud rate.
■ Make sure that characters
are read out from the re-
ceive buffer faster. To
achieve this the program
code has to be optimized.
27 / 60