Toshiba 6F3B0253 user manual CPU register ↔ T1S RS-485 port Receiving

6F3B0253

7. Instructions

CPU register ↔ T1S RS-485 port <Receiving>

When the instruction input is ON, one set of message (from start character to the trailing code) which is received by the RS-485 port is read from the receive buffer, and stored in the CPU registers. The transfer size is fixed to 256 words. The execution status and the message length (in bytes) are stored in the status flag.

The instruction input must be kept ON until the receiving operation is complete.

Example

Source designation

D0000 H0030

D0001 00000

T1S RS-485 port

Transfer size

D0002 00256 (fixed)

D0003 Execution status

D0004 Message length

Destination designation

D0005 H0004

D0006 00100

D0100 (CPU register)

When R0000 is ON, one set of received message is read and stored in D0100 and after.

Execution status:	H0000 ... Normal complete
	H0001	... Communication error (parity error, framing error)
	H0002	... Message length over (more than 512 bytes)
	H0003	... Receive buffer over flow
	H0004	... Receive time-out (from start character to the trailing code)
	Baudrate		Time-out setting
	300, 600, 1200 bps		30 seconds
	2400 bps		15 seconds
	4800 bps		7 seconds
	9600 bps		3 seconds
	19200 bps		1.5 seconds

Message length: 0 .............. No receive message

1 to 512 ... Message length in bytes

Note

•The XFER instruction is not executed as error in the following cases. In these cases, the instruction error flag (ERF = S051) is set to ON. If the ERF is set to ON once, it remains ON until resetting to OFF by user program.

(1)The leading address for the RS-485 port designation is other than 0.

(2)Transfer size is other than 256.

(3)Mode setting of the RS-485 port is not the free ASCII mode.

(4)This instruction is programmed in the sub-program #1.

Basic Hardware and Function 243