Waveshare Modbus RTU Analog Input 8CH — Web Serial Client
Reads the 8 analog input channels and configures channel range, baud rate / parity and device address directly from the browser, over Modbus RTU / Web Serial. Works with both the current-input and voltage-input ("B") hardware versions.
Product page · Wiki / register map documentation
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1. Connection
DISCONNECTED
Device address 1–255 identifies a specific unit; 0 is the broadcast address (write-only commands accept it,
reads generally don't). Factory default is 9600 baud, no parity, address 1.
Sends a broadcast read of the device-address register (0x4000) and reports whichever single device replies.
Only reliable with exactly one device on the bus — use it when the address is unknown.
2. Live Analog Inputs
| Channel | Raw register | Mode | Scaled value |
|---|---|---|---|
| Connect, read channel types once (Section 3) for correct scaling, then "Read Once" or start auto-polling. | |||
Channel History
All checked channels share one Y axis — comparing channels of different units (V vs. mA vs. raw code) will
distort the scale, so untick the ones you don't want to compare. Hover the graph for exact values.
Raw-code (mode 4) voltage/current estimate
Applies
Voltage = code × 3300 / 4095 / opamp_ratio (mV) and
Current = Voltage / sampling_resistor (mA) to channels left in mode 4 (raw code). Op-amp ratio
& sampling resistor: Standard = 32.4/49.9, 249Ω; "B" = 10/32.4, 499Ω. This is an estimate for
display only — nothing is written to the device.
3. Channel Input Type
| Channel | Mode |
|---|
4. Device Configuration
Changing baud/parity takes effect on the device immediately after the write. If you targeted
the currently connected slave address, this tool will update Section 1 and prompt you to reconnect. Only use
broadcast to set the address when a single, unconfigured device is on the bus — every listening device would
otherwise adopt the same address.