Unipi Extension xS51

Product description

Unipi Extension xS51 is an extension module communicating via the RS485 serial interface (Modbus RTU). The module is a simple and inexpensive method of extending your project by additional inputs & outputs. The xS51 features a set of analog I/Os combined with a set of digital and relay I/Os. The module is designed for installation on a DIN rail and is compatible with both Unipi Neuron and Unipi Patron controllers, as well as PLCs from other vendors.

Basic features

*more detailed info about the number and type of analog I/Os is available in the product's datasheet (see the Files tab above)

Inputs & outputs description

Digital inputs (DI) are designed to read binary logic states represented by direct voltage levels. That makes them suitable for reading data from various binary sensors and devices such as switches (on/off), motion sensors (movement detected/not detected), liquid level sensors (full tank/empty tank), etc. All digital inputs also feature counter functionality by default.

Relay outputs (RO) are primarily used for switching two-state devices with higher current draw such as lightbulbs, thermoelectric valve drives, water heaters, pumps, etc.

Analog inputs (AI) are designed to measure voltage, current, or resistance to read values from various analog sensors such as thermometers, pressure meters, tensometers, etc.

Analog outputs (AO) serve for control of multi-state external devices through direct voltage or current and is suitable for control and regulation of devices such as three-way valves, heat exchangers, electric motors, etc. 

Communication interfaces

Extension modules communicate through the RS485 interface (Modbus protocol). The connection manual for extension modules can be found on this link.

Other functions

Along with standard inputs and outputs, the module also features other functions broadening its possible uses. 

Direct Switch
This function connects digital input with digital output or relay output. The function is independent on the master PLC and is suitable for time-critical applications (ie. lighting control). The function can be configured to one of three available modes: 

• Copy: output is switched by an active input
• Invert: output is switched by an inactive input
• Toggle: output is switched by any change on the input

Default settings
This function allows the user to store the default configuration of the module into its internal memory. If the module is rebooted, the default configuration is loaded automatically. 

Master Watchdog
The function monitors the communication between the module and the controller. If the communication is interrupted (eg. no response from the controller is detected within a defined time frame), the module automatically loads the default settings. This function keeps the module operational even in case of a controller failure or software issues. 

Device addressing and DIP switch setting

Addressing the extension module can be done either via control software running on the remote master control unit or can be set manually via the integrated DIP switch. The DIP switch allows the user to set up to 4 bits of address and is evaluated in preference to software settings. If the address on DIP switch is set to “0000”, all DIP switch settings are ignored and the software settings take priority.

Package contents

• extension module
• removable screw terminals
• DIN rail holder (35 mm)
• 3× DIN rail holder mounting screws
• 1× grounding screw

Further info

• Unipi Extension connection tutorial
• Unipi product catalogue