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Doc# 1870872

 • REV A

 (January 2018) Page 

6 of 7

 

2.5 Highlight the request, and click Poll button. The register will be read and dis

-

played out.

 

2.6 In the Modbus register map, you can find the register type and address. If the 

register type is unit8, its length is 1. If the type is float32, its length is 4.

 

2.7 The register address from the map is canonical address for raw data in integer 

type. For instance, you read a float type of register from address 264, the unpro

-

cessed reading is 501785684……., but the actual value should  be a float number 

5.01785684. To get this processed float type of value, you need calculate the native 

address by using the formula (integer address x 2 + 0x8000). This is specified in the 

Modbus map manual.  

2.8 If you use the actual address in the Modbus scanner software, you will get the 

actual value of the true type.

Channel.3.Main.Type

Specifies the type of channel

uint8

0X1900

6400

N/A

RW

Channel.3.Main.PV

The process variable (output) of the 

channel

float32

0X0108

264

Set by 

Chanel.3.Main.

Resolution

RO

Channel.3.Main.Status

The PV (output) status

uint8

0X0109

265

N/A

RO

   

Summary of Contents for DATAWATCH IX Modbus

Page 1: ...DATAWATCH IX Modbus User Manual Doc 1870872 REV A January 2019 This manual provides the procedure and instruction to remotely access Metrix DATAWATCH through Modbus over TCP IP ...

Page 2: ...Doc 1870872 REV A January 2018 Page 2 of 7 Setup DATAWATCH 1 1 Log on the DATAWATCH with Engineer access level type password 100 1 2 Go to Network Modbus menu ...

Page 3: ...ge 3 of 7 1 3 Make sure Address is 1 Unit ID Enable is Loose and Serial Mode is Modbus Slave Change to these settings if they aren t 1 4 Write down the IP Address of DATAWATCH from Network Interface menu for later use by Modbus server ...

Page 4: ...the registers so that you can read them in the proper decimal numbers you want 2 Test Modbus communication from Modbus scanner software 2 1 Install the Modbus scanner software in your computer and run it 2 2 Add TCP connection using the DATAWATCH IP address and Port number ...

Page 5: ...e ID that matches DATAWATCH setting 2 4 Add request to the DATAWATCH Modbus slave The function can be either Hold ing resisters or Input registers The Offset is the register address that can be found from DATAWATCH Modbus map The Length is how many bytes the register contains ...

Page 6: ...ss 264 the unpro cessed reading is 501785684 but the actual value should be a float number 5 01785684 To get this processed float type of value you need calculate the native address by using the formula integer address x 2 0x8000 This is specified in the Modbus map manual 2 8 If you use the actual address in the Modbus scanner software you will get the actual value of the true type Channel 3 Main ...

Page 7: ... The secondary input process variable ouput of the channel float32 0X0114 276 Channel 3 Main Measured Value Measured value float32 0X1914 6420 Channel 3 Main PV The process variable output of the channel float32 0X0108 264 Channel 3 Main PV2 The secondary input process variable ouput of the channel float32 0X0118 280 Channel 4 Main Measured Value Measured value float32 0X1994 6548 Channel 4 Main P...

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