General Specifications
The ELPRO 505U-K is a wireless I/O module designed for remote monitoring of process signals. It operates in temperatures from -40 to 60ºC and humidity levels of 0-99% RH. The module is housed in an IP66 weatherproof painted aluminum enclosure and complies with EMC standards EN 300 683. It requires a power supply of 6-30 VDC.

Power Consumption
The module is energy-efficient, consuming less than 140µA in sleep mode and less than 10mA in operating mode at 12VDC. It can be powered by a 6-30 VDC supply or ELPRO BU-5 battery packs, which last up to 1.4 years depending on configuration.

Inputs and Outputs
The 505U-K supports two discrete or pulse inputs and one analogue input. Discrete inputs handle voltage-free contacts or TTL signals, while pulse inputs manage up to 10 KHz signals. The analogue input is selectable between 4-20 mA or 0-10V, with a 12-bit resolution and user-calibrated input range.

Radio Transmission
Featuring an internal 869MHz radio transmitter, the 505U-K operates on a license-free band in Europe with a line-of-sight range of up to 5km. It transmits input signal values upon change or after a pre-configured update time, with error-checking included in each message. Transmissions can be repeated multiple times for accuracy.

Mode of Operation
The module is compatible with the 105U/869 range of wireless I/O products and can interface with PLCs, DCS, or PCs. It supports up to five 905U repeaters to extend its range and can operate with more than 10,000 units in a single system.

Applications
The 505U-K is suitable for utility industries such as electricity, water, and gas, as well as short-range applications in factories and plants. It is designed for alarm, metering, and general plant monitoring applications.

Power Supply
The module requires a power supply of 6 - 30 VDC, with power consumption in quiescent mode at less than 140µA, and operating mode at less than 10mA plus analogue loop times two. During radio transmission, it consumes 300mA at 12VDC. It generates an internal analogue loop supply of 24VDC at 50mA. The module can internally monitor supply low voltage status and supply voltage, transmitting these as discrete and analogue inputs, respectively.

Inputs
The module supports various input types: discrete external status, pulse total external count, pulse rate internal analogue, analogue external analogue, setpoint internal status, supply voltage internal analogue, and supply low voltage internal status. Discrete/pulse inputs support two inputs with voltage-free contacts or NPN, or TTL voltage input. Pulse inputs have a maximum rate of 300 Hz for volt-free contacts and 10 KHz for TTL, with 50 KHz possible on PI2 using a configurable divider. Analogue inputs are selectable between 0-24mA or 0-10V, with user calibration available.

Setpoint Status
The setpoint status is activated when the analogue value is below the low setpoint and deactivated when above the high setpoint. This status is transmitted as a discrete input.

Serial Port and Radio Transmitter
The module includes an RS232 DB9 female DCE serial port for configuration and diagnostics. The radio transmitter operates at 869.4 – 869.65MHz with a fixed channel and 500mW power, conforming to EN 300 220 standards. It has a line-of-sight range of 5km, extendable with up to five 905U repeaters. Transmissions can be configured to be sent 1 to 5 times.

Configuration and Diagnostics
Configuration is managed through a Windows configuration package. The module measures digital/pulse inputs on change and every 0.5 seconds, while analogue inputs are measured based on a user-configured sample period. Input messages are transmitted to configured outputs upon input value changes or after a configured update time. A user-configurable paralysis time inhibits transmissions, and the unit powers down between measurements to conserve power.

Battery Pack
The BU-5 battery pack consists of 6 x AA alkaline batteries providing 9V, with a service life of up to 1.4 years depending on input configuration. The enclosure specifications match those of the 505U-K module, with temperature dependence based on battery type used.