Leuze 50117911, Оригинальная инструкция по эксплуатации

Страница: 160 / 231

Starting up the device - RS 485 Modbus interface
Leuze electronic GmbH + Co. KG CML 730i 160
Changeover from RS 485 Modbus to autosend ASCII protocol
14.4.2 Structure of data frame in binary format
14.4.3 Structure of data frame in ASCII format
01 = Slave address 1
05 = Write-coil command
00 00 = Address 1 (application level; counting technically begins with zero)
00 00 = OFF
FF 00 =
ON
8C 3A = CRC checksum
Message from master (PLC) to slave (CML 700i): (AUTOSEND ON)
HEX: 01 05 00 01 FF 00 DD FA
Expected answer from slave (CML 700i) to master (PLC): (AUTOSEND ON)
HEX: 01 05 00 01 FF 00 DD FA
01 = Slave address 1
05 = Write-coil command
00 01 = Address 2 (application level; counting technically begins with zero)
00 00 = OFF
FF 00 =
ON
DD FA = CRC checksum
Byte no. Direction of RS 485
(from the perspective of
the CML 700i)
Description
0 Send Number of user data bytes (n)
1 Send 8-bit checksum of all user data bytes and the number of user data bytes (checksum is the 1-byte sum
of all user data, i.e., carryovers on the 9th bit are lost)
2 … n + 1 Send n user data byte(s)
Changeover Changeover to receiving;
CML 700i waits for EOT byte (0x04) from the control (Modbus master)
Changeover Changeover to send if no EOT byte was received
n + x … Receive Repeat with byte 0, etc., if autosend is not stopped
Byte no. Direction of RS 485
(from the perspective of
the CML 700i)
Description
0 Send STX – start identifier (0x02)
1 Send Number of user data bytes (n) (4, 8, …) low byte high digit
2 Send Number of user data bytes (n) (4, 8, …) low byte low digit
3 Send Number of user data bytes (n) (4, 8, …) high byte high digit
4 Send Number of user data bytes (n) (4, 8, …) high byte low digit
5 … 5+n-1 Send n user data byte(s)
5+n Send 16-bit checksum of bytes 1 … 5+n-1 low byte high digit
5+n+1 Send 16-bit checksum of bytes 1 … 5+n-1 low byte low digit