ET-7251
Modbus TCP Based Ethernet I/O Module with 2 Ethernet ports for daisy-chain networking, with 16-channel Digital Input and can be configured as Wet Contact Sink or Source type. 32-bit counter. LED Indicators show the status of I/O. Communicable over Modbus TCP and Modbus UDP protocol, Supports operating temperatures of -25°C ~ +75°C (-13°F ~ 167°F) and has a din rail mount.
Features

The ET-7051 provides 16 wet contact digital input channels. Each input channel can be used as a 32-bit counter. It features optical isolation for 3750 Vrms of transient overvoltage protection but doesn’t provide channel-to-channel isolation. It can safely be used in applications where hazardous voltages are present.
- Built-in Web Server
- Web HMI
- Support for both Modbus TCP and Modbus UDP Protocols
- Communication Security
- 2-port Ethernet Switch for Daisy-Chain Topology
- Dual Watchdog
- Wide Operating Temperature Range: -25 ~ +75°C
- I/O Pair Connection
- Built-in I/O
- DI/Counter: 16 Channels
Applications
Building Automation, Factory Automation, Machine Automation, Remote Maintenance, Remote Diagnosis, Testing Equipment.
Daisy-Chain Ethernet Cabling
The ET-7200/PET-7200 Series has a built-in two-port Ethernet switch to implement daisy-chain topology. The cabling is much easier and total costs of cable and switch are significantly reduced.

LAN Bypass
LAN Bypass feature guarantees the Ethernet communication. It will automatically active to continue the network traffic when the ET-7200/PET-7200 looses its power.

Communication Security
Account and password are needed when logging into the web server. An IP address filter is also included, which can be used to allow or deny connections with specific IP addresses.
Support for both Modbus TCP and Modbus UDP Protocols
The Modbus TCP, Modbus UDP slave function on the Ethernet port can be used to provide data to remote SCADA software.
Built-in I/O
Various I/O components are mixed with multiple channels in a single I/O module, which provides the most cost effective I/O usage and enhances performance of the I/O operations.
Dual Watchdog
The Dual Watchdog is consists of a Module Watchdog and a Communication Watchdog. The action of AO,DO are also associated to the Dual Watchdog.
Module Watchdog is a built-in hardware circuit to monitor the operation of the module and will reset the CPU if a failure occurs in the hardware or the software. Then the Power-on Value of AO,DO will be loaded.
Communication Watchdog is a software function to monitor the communication between the host and the I/O module. The timeout of the communication Watchdog is proprgrammable, when the I/O doesn't receive commands from the host for a while, the watchdog forces the AO,DO to pre-programmed Safe Value to prevent unpredicatable damage of the connected devices.
Highly Reliable Under Harsh Environment
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I/O Pair ConnectionThis function is used to create a AI/DI to AO/DO pair through the Ethernet. Once the configuration is completed, the I/O module can poll the status of remote AI/DI devices and then use the Modbus TCP protocol to continuously write to a local AO/DO channels in the background. |
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Power-on Value and Safe Value
Besides setting by the set AO,DO commands, the AO,DO can be set under two other conditions.
Power-on Value: The Power-on Value is loaded into the AO,DO under 3 conditions: Power-on, reset by Module Watchdog, reset by reset command.
Safe Value: When the Communication Watchdog is enabled and a Communication Watchdog timeout occurs, the “safe value” is loaded into the AO,DO.
Specifications
Software | |
Built-In Web Server | Yes |
Web HMI | Yes |
I/O Pair Connection | Yes |
Communication | |
Ethernet Port | 2 x RJ-45, 10/100 Base-TX, Swtich Ports |
PoE | - |
Protocol | Modbus/TCP, Modbus/UDP |
Security | ID, Password and IP Filter |
Dual Watchdog | Yes, Module (0.8 second), Communication (Programmable) |
LED Indicators | |
for System Running | Yes |
for Ethernet Link/Act | Yes |
for DI/DO status | Yes |
for PoE Power | - |
2-Way Isolation | |
Ethernet | 1500 VDC |
I/O | 2500 VDC |
EMS Protection | |
ESD (IEC 61000-4-2) | 4 kV Contact for Each Terminal and 8 kV Air for Random Point |
EFT (IEC 61000-4-4) | +/-4 kV for Power |
Power Requirements | |
Reverse Polarity Protection | Yes |
Powered from Terminal Block | 12 ~ 48 VDC |
Powered from PoE | - |
Consumption | 2.9 W |
Mechanical | |
Dimensions (W x L x H) | 76 mm x 120 mm x 38 mm |
Installation | DIN-Rail or Wall mounting |
Environmental | |
Operating Temperature | -25 ~ +75°C |
Storage Temperature | -30 ~ +80°C |
Humidity | 10 ~ 90% RH, Non-condensing |
I/O Specifications
Digital Input/Counter | ||
Channels | 16 | |
Contact | Wet Contact | |
Sink/Source (NPN/PNP) | Sink/Source | |
On Voltage Level | +10 VDC ~ +50 VDC | |
Off Voltage Level | +4 VDC Max. | |
Input Impedance | 10 kΩ | |
Counters | Max. Count | 4,294,967,285 (32 bits) |
Max. Input Frequency | 100 Hz | |
Min. Pulse Width | 5 ms | |
Overvoltage Protection | +70 VDC |