MultiTrode MultiSmart Installation & Operation Manual page 189

MultiSmart Installation & Operation Manual
22.2.2.4 Modbus Slave
This menu gives access to viewing and editing of the points list configurations of all the Modbus Slaves
present. To switch between the subsequent slaves (if more than one slave is present), press Next Slave or
Prev Slave at the bottom of the LCD screen. The screen title in that menu shows the information about the
currently selected slave. All discrete inputs, coils, input registers and holding registers can be viewed under
this menu. The properties of the points can be edited as well as new points can be added in their respective
categories by accessing the corresponding sub sections.
To add a new point browse to the corresponding section as shown below and select Add New.
Select the appropriate slave settings from the list below:
•
Discrete Inputs
•
Coils
•
Input Registers
•
Holding Registers
To add a new point, click
You may have to select the appropriate slave using "Next Slave" or "Previous Slave" buttons, which are
visible if more than one slave is configured.
NOTE:
Modbus only supports 16-bit integers for Input Registers and Holding Registers, whereas MultiSmart
tags are stored as 32-bit numbers. If a value greater than the 16-bit range (maximum of 65,535) is
represented as an Input Register or Holding Register, then the value will roll-over back to zero and be
misrepresented. In order to prevent this from happening, appropriate scale factors need to be applied to
ensure that values remain within range of 16-bit representations.
The potential for this problem is especially with floating point values. For example, the level of the well is
represented as a value between 0 and 100, with four decimal places. This means that a value of 100 is
represented in integer form as 1,000,000. A scale factor of 10,000 will limit the range to 0 and 100 with
zero decimal places, and ensure that the level is always accurately represented.
22.2.2.5 Modbus Master
This menu gives access to viewing and editing of the slave profiles of all the Modbus slaves configured
under all the Modbus masters created in the MultiSmart unit. To switch between the different slave profiles (if
there are more than one present), press Next Slave or Prev Slave at the bottom of the LCD screen. The
screen title in that menu shows the information about the currently selected master slave pair. Similar to the
Modbus Slave menu, all discrete inputs, coils, input registers and holding registers can be viewed under this
menu. The properties of the points can be edited as well as new points can be added in their respective
categories by accessing the corresponding sub sections.
Select the appropriate slave settings from the list below:
•
Discrete Inputs
•
Coils
•
Input Registers
•
Holding Registers
To add a new point browse, click
You may have to select the appropriate slave using "Next Slave" or "Previous Slave" buttons, which are
visible if more than one slave is configured under the same master or if multiple masters are present.
MultiSmart_IO_Manual_R20
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