Table 25:
Basic diagnostic counters
Counter
Function
Characters received
Counts all incoming non-erroneous characters. This
counter operates regardless of if the serial driver is
set to detect a whole protocol link frame or just
separate characters.
Frames received
Counts all protocol specific non-erroneous frames
received. Protocol-specific frames can be based on
timing (for example, Modbus RTU) or on special start
and stop characters (for example, Modbus ASCII).
Frames discarded
Counts all protocol-specific erroneous frames
received. If the driver detects an error while receiving
a frame, the frame is automatically discarded. This
also means that the protocol in question will never
receive a faulty frame from the driver. When this
counter is increased, one of the detailed error
counters is also incremented.
Frames transmitted
Counts all protocol-specific frames transmitted from
the COM channel.
Table 26:
Detailed error counters
Counter
Function
CD Lost
In RS-232 handshake mode, characters are to be
received as long as Carrier Detect (CD) signal is
active. This counter is incremented if the CD signal is
lost during reception.
Collision
Counts transmission collisions. Used in RS-485
mode by some protocols where transmissions could
collide. For example, DNP3 unsolicited mode.
CTS Timeout.
In RS-232 handshake mode the Clear To Send
(CTS) signal is not received as reply to this device
Request To Send (RTS) signal.
Transmission timeout.
In RS-232 handshake mode. If the CTS signal goes
inactive during transmission then the transmission is
halted. Transmission will be resumed when CTS
goes active again. The whole frame transmission
must anyhow be ready within a specified time. If this
timeout elapses then this counter is incremented.
Result will be that the end of the frame is not being
transmitted out.
Parity errors
Counts parity errors detected in characters.
Overrun errors
Counts overrun errors detected in characters.
Framing errors
Counts framing errors detected in characters
1MAC456939-IB D
Section 8
Commissioning
620 series ANSI
125
Operation Manual