Serial Link Diagnostics And Monitoring - ABB RELION REX640 Technical Manual

Basic functions
3.2.12

Serial link diagnostics and monitoring

Serial communication diagnostics and monitoring is divided between the serial link
driver and the serial communication protocol. The lower-level physical and protocol-
independent aspects of the UART-based serial communication are monitored in the
serial link driver. Diagnostic counters and monitoring values are located on the HMI
under Monitoring > Communication > COMn (n= 1,2,...).
Depending on the communication protocol, the serial driver software receives single
characters or complete protocol frames, based on the frame start/stop characters
or on link frame timing.
Table 41: Setting parameters
Parameter
Fiber mode
Serial mode
Baudrate
Table 42: Diagnostic counters and indications
Counters
Characters received
Frames received
Frames discarded
Frames transmitted
Collisions
Parity errors
Overrun errors
Framing errors
Link status
Link status
94
Description
Defines the fiber-optic mode used. Setting "No fiber" is the
same as galvanic mode.
Used for galvanic RS-485 modes 2- or 4-wire. This setting is
relevant only if Fiber mode is set to "No fiber".
Communication speed used.
Description
Counts all incoming non-erroneous characters. This counter
operates regardless of whether the serial driver is set to de-
tect a whole protocol link frame or just separate characters.
Counts all protocol-specific non-erroneous frames received.
Protocol-specific frames can be based on timing (for exam-
ple, Modbus RTU) or on special start and stop characters (for
example, Modbus ASCII).
Counts all protocol-specific erroneous frames received. If the
driver detects an error while receiving a frame, the whole
frame is automatically discarded. This also means that the
protocol in question never receives a faulty link frame from
the driver. When this counter is incremented, one of the de-
tailed error counters (Parity, Overrun, Framing) can also be
incremented.
Counts all protocol-specific frames transmitted from the
COM channel.
Counts the number of transmission collisions that have oc-
curred. Used in RS-485 mode by some protocols where trans-
missions could collide with reception. For example, DNP3 un-
solicited reporting mode.
Counts the number of parity errors detected in characters
received.
Counts the number of overrun errors detected in characters
received.
Counts the number of framing errors detected in characters
received.
In write direction: By writing value 1 to this parameter, all the
diagnostic counters are reset to 0.
In monitoring direction: If the driver instance is in use by any
communication protocol, the monitoring value shows value
1. Otherwise, the value is 0.
1MRS759142 F
REX640
Technical Manual