Environmental and process data
Collect values from compatible temperature, humidity, level, pressure, water-quality and other RS485 sensors.
RS485 Cloud Data Logger · Y921
Collect RS485 Field Data and Send It to the Cloud
Y921 connects Modbus RTU sensors, meters and controllers through four RS485 interfaces, then reports the selected data through 4G, Wi-Fi or Ethernet.
- 4 × RS485 field interfaces
- Modbus RTU collection
- 4G, Wi-Fi or RJ45 model
- Cloud-configured collection points
Y921 is a data-acquisition product. It does not control field devices.
Data acquisition
Connect Sensors, Meters and Controllers
Use four RS485 buses to collect selected Modbus RTU registers. Configure the point list and collection parameters in YenGear IoT Cloud.
Measurement data
Read compatible power meters, flowmeters and other Modbus RTU instruments.
Status and measurements
Read published registers from PLCs, controllers and equipment without taking over their control function.
Data path
From Modbus Register to Cloud Record
The network must be available for collection and reporting. Y921 has no standard offline collection, cache or backfill function.
01Field deviceSensor, meter, PLC or controller
02RS485 Modbus RTURead configured slave registers
03Y921 uplink4G, Wi-Fi or RJ45 Ethernet
04Cloud dataCurrent values, history and configured alarms
Network interruption: Y921 does not collect or store readings during the outage. After reconnection, it resumes current data collection without backfilling the missing period.
Model selection
Choose One Uplink for the Standard Model
G, W and R identify the standard uplink. Combined uplinks require project engineering.
For distributed sites without usable Wi-Fi or wired Ethernet.
For sites with a stable wireless LAN and approved access credentials.
For control rooms, electrical rooms and field panels with a stable wired network.
Standard and custom
Keep the Standard Product Separate from Project Engineering
The standard product collects RS485 Modbus RTU data. Other interfaces, protocols and integrations are confirmed per project.
Four-port RS485 data collection
- 4 × RS485 interfaces
- Modbus RTU
- One uplink type
- Data acquisition and reporting
Interfaces, protocols and platforms
- RS232
- Analog acquisition
- Combined uplinks or other serial protocols
- Third-party platform integration
No field control: choose a control-capable product when the project must start, stop or regulate pumps, fans, lighting or other loads.
Technical reference
Standard Configuration Summary
Use the product specification and the approved point list to confirm the final collection configuration.
Field interfaces
- Quantity
- 4 × RS485
- Protocol
- Modbus RTU
- Connected devices
- Sensors, meters and controllers
Uplink models
- Y921-G
- 4G
- Y921-W
- Wi-Fi
- Y921-R
- RJ45 Ethernet
Operating boundary
- Role
- Collection and reporting
- Field control
- Not supported
- Offline records
- No collection, cache or backfill
FAQ
Interfaces, Networking and Offline Behavior
How many field interfaces does the standard Y921 provide?
The standard Y921 provides four RS485 interfaces and collects data from devices that use Modbus RTU.
What is the difference between Y921-G, Y921-W and Y921-R?
Their uplink networks are different: Y921-G uses 4G, Y921-W uses Wi-Fi and Y921-R uses RJ45 Ethernet. Each standard model includes one uplink type.
Can an analog sensor connect directly to the standard Y921?
Not to the standard model. Analog acquisition can be engineered for a project or handled with an appropriate signal-conversion device.
Can Y921 remotely control a pump or fan?
No. Y921 collects and reports data; it does not control field equipment. Use a product with verified control outputs for remote switching.
Does Y921 save readings while its network is unavailable?
No. During a network interruption, Y921 does not collect, cache or backfill data for that period. It reconnects and resumes real-time collection after the network returns.
Where are collection points and Modbus parameters configured?
They are configured in YenGear IoT Cloud, including slave address, register address, data type, byte order, scaling and collection interval.
Can Y921 connect to a third-party platform?
Third-party platform integration is available as project engineering. Scope depends on the target protocol, authentication, data format and joint testing.
How many devices can one Y921 collect from?
The practical device and point count depends on baud rate, register count, collection interval and RS485 communication quality. Confirm it against the actual point list.
Project review
Share the Device List, Register Map and Site Network
Provide device models, quantities, Modbus registers, required data, collection intervals and network conditions so the technical team can confirm the Y921 model and configuration.