This driver is a simple driver. It provides additional functionality to enable Geo SCADA Expert to interface with specific supported devices using a particular protocol. To interact successfully with such devices, you need to:
- Install and run the driver
- Ensure that the driver is licensed
- Configure the required database items and settings on the driver
- Ensure that the database items (and any database items on which they depend) have valid, saved, configuration and are 'In Service'.
Intended Audience
This guide is primarily intended for engineers who are responsible for configuring Modbus Slave items and features in the Geo SCADA Expert database.
The guide also contains information for maintenance engineers.
Document Scope
This guide explains the configuration, features and database items that are specific to Geo SCADA Expert’s Modbus Slave driver. The Modbus Slave driver enables Geo SCADA Expert to act as a Modbus PLC and report any data changes back to its Master, using the Modbus protocol.
For information on how to configure Geo SCADA Expert to communicate with slave devices and PLCs using the Modbus protocol, see the Geo SCADA Expert Guide to the Advanced Modbus Driver, or the Geo SCADA Expert Guide to the Simple Modbus Driver (as applicable).
Prerequisite Reading
This guide contains technical information that is intended for users that are sufficiently familiar with Geo SCADA Expert configuration and operation. Before reading this driver guide, ensure that you are familiar with:
- Geo SCADA Expert configuration practices, procedures, and the configuration of properties that are common to many database items. For more information, see the Geo SCADA Expert Guide to Core Configuration, and the Geo SCADA Expert Guide to Core Point Configuration.
- Driver structure, components, and configuration properties, pick actions, and status attributes that are common to many drivers. For more information, see the Geo SCADA Expert Guide to Drivers.
- Simple driver composition, configuration order, and configuration properties and logging options that are common to many simple drivers. For more information, see the Geo SCADA Expert Guide to Simple Drivers.
The Slave can obtain its data directly from plant, from calculated values, or from any item in the Geo SCADA Expert database. Its Master can be another Geo SCADA Expert server, or a third party server that is using the Modbus protocol.
The Modbus Slave Driver provides extra functionality within a Geo SCADA Expert server for transmitting data or controlling points. A Modbus Slave uses Value Maps for mapping point properties into memory, so that they can be accessed by the Modbus protocol.
The Modbus Slave documentation explains how to configure Modbus Slave-specific features and items within the Geo SCADA Expert database—see, as applicable:
- Configuring Modbus Slave Devices in Geo SCADA Expert
- Using Value Maps to Represent Modbus Data Address Ranges
- Modbus Function Codes Supported by the Geo SCADA Expert Modbus Slave Driver
- Typical Scenarios.
It also explains driver-specific aspects that are of interest to system administrators and engineers when investigating unexpected system behavior (relating to the Modbus Slave driver):
NOTE: There are no driver-specific pick actions for database items on this particular driver. However, users with the required privileges can add custom pick actions to a database item by using the User Methods tab on the relevant configuration Form (see Using the User Methods Tab to Define Custom Actions in the Geo SCADA Expert Guide to Core Configuration). See a system administrator for the documentation associated with such custom actions (also known as ‘methods’).