Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 169)

9–31 Diagnostic Counters
Publication 1770Ć6.5.16 - October 1996
Below are diagnostic counters for the channel 0 serial port.
These counters vary depending on whether the port is configured for:
•
point-to-point (full-duplex)
•
half-duplex slave
•
half-duplex master
This counter byte Counts the number of
0, 1
General status words.
Contains serial port information as defined below:
• 0 Bit 0: status of CTS (1 = asserted, 0 = deasserted)
Bit 1: status of RTS (1 = asserted, 0 = deasserted)
Bit 2: status of DSR (1 = asserted, 0 = deasserted)
Bit 3: status of DCD (1 = asserted, 0 = deasserted)
Bit 4: status of DTR (1 = asserted, 0 = deasserted)
Bit 5: status of modem connection (1 = lost)
Bits 6, 7: reserved
• 1 Bits 8Ć11: mode of serial port (0000 = system, 0001 = 1
user)
Bits 12Ć14: reserved (set to 0)
Bit 15: input buffer overflow (user mode only). More than
256 characters have been received before the
execution of an ASCII read instruction.
2, 3 Messages sent (indicating retries).
4, 5 Messages received with proper BCC or CRC.
6, 7 Undelivered messages.
8, 9 ENQs sent.
For this protocol This is the number of
fullĆduplex ENQs sent
half duplex message retries
10, 11 NAKs received.
12, 13 ENQs received.
14, 15 Bad packets received - packets received with incorrect BCC or
CRC.
16, 17 NAKs sent.
18, 19 Duplicate messages received.
20, 21 Received errors (user mode only).
Number of characters thrown away due to parity, overflow, and
framing errors.
22, 23 Number of times DCD went low and then high - DCD recovered.
24, 25 Number of times modem connection was lost.