Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 270

CPM2A/CPM2C Communications Functions
Ladder Program
(Mnemonics)
250
The unsolicited Host Link communications are executed using TXD(48).
Mnemonic Control
(@)TXD(48) Communications port
output
Host Link communications are controlled with the following AR area flags.
Word Bit(s)
AR 08 00 to 03 RS-232C Port Error Code
0: Normal completion
2: Frame error
04 RS-232C Communications Error Flag
ON: RS-232C port communications error occurred
OFF: Normal
05 RS-232C Transmit Ready Flag
ON: The PC is ready to transmit data.
08 to 11 Peripheral Port Error Code
0: Normal completion
2: Frame error
12 Peripheral Port Communications Error Flag
ON: Peripheral port communications error occurred.
13 Peripheral Port Transmit Ready Flag
ON: The PC is ready to transmit data.
Unsolicited Communications
A data transmission to the host computer is initiated by the PC.
(@)TXD(48)
S: Leading address of data to be transmitted
S
C C: Control data
N N: Number of bytes to be transmitted (BCD: 0001 to 0061)
When Host Link communications are being used, TXD(48) converts the N-bytes
of data starting at S to ASCII, adds the Host Link header, FCS, and terminator,
and transmits this data as a Host Link frame.
The transmitted Host Link frame will be as shown in the following diagram.
Node No.
Reads data from I/O memory and transmits
it in the specified frame format.
Contents
1: Parity error
3: Overrun error
1: Parity error
3: Overrun error
Communications port
0: RS-232 port; 1: Peripheral port
Converted to ASCII.
N bytes
Data (ASCII)
Section 4-3
Contents