Utility programs and protocols
126 MCS100E Operating Instructions 8009504/V YWA7/V3-1/2018-01 © SICK AG
Subject to change without notice
9.3 Modbus protocol
Menu: Specialist: System edit: Data storage and send to PC
MCS100E program revision 1.42
Modbus RTU protocol
Definition which registers are sent and received from the external PC
+------------------------------------------------------------------------------+
¦Address¦ Register offset ¦coil offset digital ¦ ¦
¦Offset ¦Block1¦Block2¦Digit.¦Compon¦System¦DatLog¦OUTPUT¦INPUT ¦FLAG ¦ ¦
¦ 0 ¦0 ¦100 ¦68 ¦200 ¦1400 ¦1500 ¦0 ¦96 ¦192 ¦ ¦
¦first byte send : high ¦
¦Result,Comp.data type : 32bit floating point 2 register ¦
¦16 bit data factor : 100 ¦
¦Julian date offset : 578041 default: 578041 ¦
¦Modbus master settings: (Function,Start register/coil,No. register/coil) ¦
¦SlaveAddr:0 ¦SlaveAddr:0 ¦SlaveAddr:0 ¦SlaveAddr:0 ¦SlaveAddr:0 ¦ ¦
¦Fnc¦Start¦No. ¦Fnc¦Start¦No. ¦Fnc¦Start¦No. ¦Fnc¦Start¦No. ¦Fnc¦Start¦No. ¦ ¦
|1 |1 |8 |1 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
|3 |5 |12 |15 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
|15 |97 |16 |3 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
|16 |105 |12 |16 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
|0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
|0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0 | ¦
¦ ¦
¦Timeout for new Modbus message (*55ms) : 2 ¦
¦ ¦
+------------------------------------------------------------------------------+
Datatransfer MCS100E <---> PC with serial interface and Modbus RTU protocol
Start the message with a silent of at least 3.5 character times
Byte
1 address
2 function
3 data
:
last-1 LSB CRC-check
last MSB CRC-check
Address Offset
! The Address Offset is
!added to Start Register by sending always
!and subtracted by receiving only when Start Register > Address Offset.
Modbus Master:
function
01 : Read multiple coil
Demand of digital I/O/FLAG from Slave
15 : Force multiple coil
Send of digital I/O/FLAG to Slave
05 : Force single coil
Send one digital I/O/FLAG to Slave
03 : Read multiple register
Demand of Results,Component values,Modbus-Systemparameter
16 : Write multiple register
Send of Results,Component values,Modbus-Systemparameter
with the definition from above
demand : Results R1,R2,R3,R4,R5,R6
digital OUT DO1,DO2,DO3,DO4,DO5,DO6,DO7,DO8
send : Results R33,R34,R35,R36,R37,R38
digital INP DI01..DI16
digital OUT DO1
Modbus Slave:
Exception response if illegal data address