7 Application Instructions API 50-99 Sending data: (PLC -> external equipment) Head code source data register, starting from the lower 8 bits of D100 Tail code 1 Tail code 2 length = 4 Receiving data: (External equipment -> PLC) When receiving data, PLC will receive the head code and tail code of the data from the external equipment; therefore, the user has to be aware of the setting of data length n . 2. 16-bit mode: The head code and tail code of the data are set up by M1126 and M1130 together with D1124 ~ D1126. When PLC is executing RS instruction, the head code and tail code set up by the user will be sent out automatically. M1161 = Off indicates PLC in 16-bit conversion mode.
The 16-bit data will be divided into the higher 8 bits and lower 8 bits for data transmission. M1001 M1161 X0 Sending data: (PLC -> external equipment) Head code source data register, starting from the lower 8 bits of D100 Tail code 1 Tail code 2 length = 4 Receiving data:
(External equipment -> PLC) Head code Tail code 1 Tail code 2 received data register, starting from the lower 8 bits of D120 length = 7 DVP-PLC APPLICATION MANUAL 7-99 STX D100L D101L D102L D103L ETX1 ETX2 D120L D121L D122L D123L D124L D125L D126L Head received data register, starting from Tail code Tail code code the lower 8 bits of D120 1 2 length = 7 RS D100 K4 D120 K7 STX D100L D100L D101L D101L ETX1 ETX2 D120L D120H D121L D121H D122L D122H D123L