ET-2217H / PET-2217H: 8 kHz analog input module for real-time applications

ICP DAS has introduced a next-generation industrial I/O module — ET-2217H / PET-2217H, designed for high-precision and high-speed analog data acquisition. The new module has 8 differential channels with a sampling frequency of up to 8 kHz and supports a wide range of industrial protocols.

ET-2217H / PET-2217H is a high-speed analog input module equipped with 8 differential channels. Each channel can be individually configured to one of the following input signal ranges: ±2.5 V, 0–5 V, ±5 V, 0–10 V, ±10 V, 0–20 mA, 4–20 mA, and ±20 mA. The input type is selected using a DIP switch: either voltage or current.

The I/O module provides overvoltage protection up to 50 VDC and overcurrent protection up to 50 mA at 50 VDC/AC.

With a sampling rate of up to 8 kHz (all channels total), the ET-2217H / PET-2217H supports continuous data transfer mode (TCP Streaming) for recording current and voltage values in real time.

Additionally, the module comes with EMS protection (EFT, ESD, Surge) and 3000 VDC input/output isolation, which ensures reliable operation even in conditions of strong electromagnetic interference and industrial noise.

Key features:

• Web interface for configuration: convenient set-up via browser
• Communication protocols support:
• TCP Streaming (continuous data transmission)
• Modbus TCP/UDP
• MQTT
• SNMP V2c
• Built-in 2-port Ethernet switch (LAN Bypass) - for cascade connection without additional equipment
• Dual Watchdog provides high reliability
• I/O Pair Connection Function - Push/Pull Mode
• Integrated I/O
• 8-channel differential analog input with high data processing speed

After starting the ADC, the data is continuously transmitted to the host computer. The user can specify the required channels for collection. The sampling frequency depends on the number of channels:

TCP Streaming operational mode

Continuous data collection mode uses TCP Streaming to transfer collected information to a PC. The operating principle is based on polling scanning implemented in the module firmware, while the sampling frequency is fixed.

The process goes as following:

• The module periodically polls its analog inputs and stores data in an internal buffer.
• When the volume of accumulated data reaches a certain threshold, it is automatically sent to the host.
• The PC (host) initiates collection by sending a start command.
• The module begins transmitting large data packets in accordance with the described mechanism until the host sends a stop command, completing the collection.

This approach ensures stable and efficient transmission of large volumes of data in real time.

TCP Streaming data format

The module supports data streaming (TCP Streaming) with a fixed sampling frequency of 8 kHz. The manufacturer provided a diagram of the transmitted packet format, but specified that when using the official SDK, the user only receives analog input values (AI values) - service information (headers, channel identifiers, counters) is processed inside the SDK and is not directly accessible. TCP Streaming implements a packet sequence counter, which allows you to determine whether data in the stream has been lost or corrupted. This mechanism is also hidden from the user and is automatically processed by the SDK.

Modbus/TCP (Query-Reply mode)

This mode is one of the most common ways of exchanging data with data collection modules.

The process goes as following:

• The module collects data at a fixed sampling rate.
• The obtained values are temporarily stored in the module's internal memory, in the Modbus register table.
• When receiving a request from the host (PC or controller), the module sends back only the necessary data, retrieving them from memory.

This method works best for systems where a certain data update frequency and a standard communication protocol are required.

Comparison table of the ET-2217 series