MC³ 24.96.EX O&M Manual Page 60 08/14/01 4:34 PM/LDD
Counter Description
D Number of messages received with a bad message format.
E Number of Communication Interrupts. This counter increments for
every character received or transmitted.
F Last Serial Communications UART Status word with an error bit
set. See LSR - on page 60.
IIR -
This is the value in the UART Interrupt Identification Register. It is bit coded according to the
following table:
Bit Description
0 Modem status changed
1 No interrupt pending
2 Transmitter buffer empty
3 No interrupt pending
4 Receiver buffer full
5 No interrupt pending
6 Receiver buffer full and receive character error
7 No interrupt pending
LSR -
This is the value in the UART Line Status Register. It is bit coded according to the following table:
Bit #r Description
Bit 7 Not used.
Bit 6 Transmitter Empty - holding register and shift register.
Bit 5 Transmitter holding register empty.
Bit 4 Break detected.
Bit 3 Framing Error
Bit 2 Parity Error
Bit 1 Overrun Error
Bit 0 RxRD Receive Data Ready
TX -
This is the status of the message transmitter function.
Value Description
0 Transmitter passive
1 Transmitter active
2 The last byte of the telegram is being transmitted