mvi56 modbus setting

MVI56-MCM Modbus Card Setting

USING THE CARD AS MODBUS MASTER

WriteData means the data passed onto Modbus Slave with Function Codes: 5 (Single Coil Write), 6 (Single Register Write), 15 (Multiple Coil Write), 16 (Multiple Register Write)

ReadData means the data received from Modbus Slave in response to Fuction Codes: 1 (Read Output Status), 2 (Read Input Status), 3 (Read Multiple Registers), 4 (Read Input Registers).

First Define following (assuming you have 200 words of data to be read & another 200 words to be written)–

MCM.ModDef.WriteStartReg = 200MCM.ModDef.WriteRegCnt = 200MCM.ModDef.ReadStartReg = 0MCM.ModDef.ReadRegCnt = 200

This means the ReadData from ReadData[0] to ReadData[199] will correspond to the first 200 registers of the MCM Internal memory (Internal Address 0 to 199) and the WriteData from WriteData[0] to WiteData[199] will correspond to next 200 registers in the MCM memory (Internal Address 200 to 399)

Now define the MCM Port to work as Modbus Master by setting the different parameters in MCM.Port –

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The value in CmdCount will configure the number of Modbus Master commands that the module will issue to the various slave devices. Example – A value of 3 in this field will allow the master to look at P3.Cmd[0] to P3.Cmd[2]

The values in BitInOffset, WordInOffset, OutOffset, and HoldOffset will configure the internal database offset values WHEN THE PORT IS CONFIGURED AS SLAVE. (Not required in Master mode configuration)

Master Command Configuration :

Example A

The above Modbus Command shall issue Function Code : 3 Read Multiple Registers From Slave ID 1 Total Count of 10 RegistersStarting from 0 (i.e. Modbus Address #40001)& put them into MCM Internal Memory Register starting from 10 (i.e. MCMReadData[10] onwards)



Hence if the Slave ID 1, has following data Register Data,

Then following will appear in the MCMReadData –

- - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -



Example B

The above Modbus Command shall issue Function Code : 1 Read Output Status From Slave ID 1 Total Count of 16 Bits (Note Bits here, since FC is 1)Starting from 0 (i.e. Modbus Address #1 in the slave device)& put them into MCM Internal Memory Bit starting from 16 (i.e. MCMReadData[1].0 onwards) {MCMRedData[0] will have bits 0 to 15}

Hence if the Slave ID 1, has following Output Status Data,



Then following will appear in the MCMReadData –

- - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -

Example C

The above Modbus Command shall issue Function Code : 16 Write Multiple Registers To Slave ID 1 Total Count of 8 RegistersStarting from MCM Internal Memory Register # 200 (corresponding to MCMWriteData[0] onwards)& put them into Slave Device Memory Register # 10 onwards (i.e. Modbus Address #40011 onwards in the slave device)



Hence if the MCMWriteData has following values –

Then following will appear in the Modbus Memory Addresses of the Slave –



Now if we connect a Hyper-terminal to the CFG Port of the Prosoft Module and navigate to see the Master Command List of Port 2, following will be displayed –



USING THE CARD AS MODBUS SLAVE

The module has a 5000 register database. Register 0 to register 4999It must be defined in 200 word increments for ReaDdata and WriteData.

WriteData means the data passed onto Modbus Master when responding to Function Codes 1 (Read Output Status), 2 (Read Input Status), 3 (Read Multiple Registers), 4 (Read Input Registers).

ReadData means the data received from Modbus Mater with Fuction Codes: 5 (Single Coil Write), 6 (Single Register Write), 15 (Multiple Coil Write), 16 (Multiple Register Write)

First Define following (assuming you have 200 words of data to be passed onto & another 200 words to be received)–

MCM.ModDef.WriteStartReg = 200 MCM.ModDef.WriteRegCnt = 200MCM.ModDef.ReadStartReg = 0 MCM.ModDef.ReadRegCnt = 200

This means the ReadData from ReadData[0] to ReadData[199] will correspond to the first 200 registers of the MCM Internal memory (Internal Address 0 to 199) and the WriteData from WriteData[0] to WiteData[199] will correspond to next 200 registers in the MCM memory (Internal Address 200 to 399)

Now define the MCM Port to work as Modbus Slave by setting the different parameters in MCM.Port –



The mapping that you require is done with the settings: MCM.Port*.BitInOffset = (Offset value represents the MCM Int. memory database address where Modbus bit address 10001 will start at. Function codes 2)

MCM.Port*.WordInOffset = (Offset value represents the MCM Int memory database address where Modbus bit address 30001 will start at. Function code 4)

MCM.Port*.OutOffset = (Offset value represents the MCM Int. memory database address where Modbus bit address 0001 will start at. Function codes 1,5,15)

MCM.Port*.HoldOffset= (Offset value represents the MCM Int. memory database address where Modbus bit address 40001 will start at. Function codes 3,6,16)

For Example –

Assume we have to configure the MVI56-MCM as Modbus Slave, for following -

FC = 2, Read Input From Address 10001 to 10320 (i.e. 20 words of data : 320/16 = 20)

FC = 3, Read Input Register From Address 30001 to 30006

FC = 15, Force Multiple CoilFrom Address 1 to 16 FC = 16, Multiple Register WriteFrom Address 40001 to 40009

So for this scenario, we will use the following setup:

MCM.Port*.BitInOffset = 200MCM.Port*.WordInOffset = 220MCM.Port*.OutOffset =0 MCM.Port*.HoldOffset= 10 (we reserved 0 – 9 words for Outoffset)



Now, if we have following data in the WriteData Registers -



The same will appear at the Modbus Master at 10001 onwards, in response to Function Code 2 –



For FC = 3, Read Input Register, the data at the WriteData[20] onwards shall be supplied –

& the same will appear at Modbus Master –



For FC = 15, Force Multiple Coil, if following is set from the Master –

Then the same will be written to ReadData[0] as –



Similarly for FC = 16, Multiple Register Write, if the Master sets as following –

Then the same will be written to ReadData[10] onwards as –


mvi56 modbus setting

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