Installation Manual — Rev 1.0
E860 DTU
LoRa Water Control
Point-to-point LoRa radio system for automated borehole pump control using a float switch at the reservoir. Designed for Tambuki ground-crew installation.
01
System Overview
This system automatically controls a borehole pump based on the water level in the Tambuki reservoir. When the tank runs low, a float switch triggers a chain of LoRa radio signals that switches the borehole pump ON. When the tank is full, the pump switches OFF — all wirelessly, no SIM or internet needed.
ℹ️ What is LoRa? LoRa is a long-range low-power radio. These devices talk directly to each other over several kilometres — like a walkie-talkie for equipment signals. No phone signal or wifi needed.
Fig 1.1 — Full system signal flow (live animation)
🔢 Devices in This System
4x E860 DTU V1 total:
Device 1 — Reservoir: MASTER (reads float switch)
Device 2 — Central: SLAVE (receives from reservoir)
Device 3 — Central: MASTER (sends to borehole)
Device 4 — Borehole: SLAVE (fires pump contactor)
Devices 2 and 3 are hardwired together at central site.
✅ Already Tested
Point-to-point LoRa transmission between E860 devices has been confirmed working. Signal path and pairing are proven.
Good news: Radios are pre-paired. No radio configuration needed on site.
02
How It Works — Step by Step
Follow the signal from the tank all the way to the borehole pump. This shows what happens when the tank runs low.
Fig 2.1 — Signal chain when tank runs low (animated)
ℹ️ When tank is FULL: Float rises, switch opens, Master stops transmitting, Slave relay opens, contactor drops out, pump stops automatically.
03
Site Locations & Antenna Mast Heights
Each E860 must be mounted at height with a clear line of sight to the next site. Higher is better for LoRa range. Required mast heights:
🌊
As High
as possible
as possible
Target ≈ 8m
Reservoir (Tambuki) Site
Mount as high as the pole allows. Tank / float switch location.
📡
As High
as possible
as possible
Target ≈ 15m — PAKSTOOR MAST
Central Relay Site
The Pakstoor mast. Must be the highest point. Relay between both sites.
⛏️
As High
as possible
as possible
Target ≈ 8m
Borehole Site
Mount as high as the pole allows. Pump control location.
Fig 3.1 — Mast heights at each site with animated LoRa signals
⚠️ Important: Antennas must have line of sight between sites. Do not mount behind buildings, trees or hills. The Pakstoor central mast is the relay between the other two — it must be the highest point.
🔴 ANTENNA RULES — CRITICAL:
1. Magnetic base antennas only — these must be mounted on a flat metal surface so the magnet holds firmly.
2. Perfectly vertical — the antenna must point straight up. Even a small tilt kills range. Use a spirit level if needed.
3. Not obscured — the antenna must be the topmost item on the mast. Nothing above it, nothing beside it at the same height.
4. No extension coax cables — the E860 unit must be mounted directly at the antenna location. The entire unit goes up the mast in a waterproof enclosure. Power cable (not antenna cable) runs down the pole.
1. Magnetic base antennas only — these must be mounted on a flat metal surface so the magnet holds firmly.
2. Perfectly vertical — the antenna must point straight up. Even a small tilt kills range. Use a spirit level if needed.
3. Not obscured — the antenna must be the topmost item on the mast. Nothing above it, nothing beside it at the same height.
4. No extension coax cables — the E860 unit must be mounted directly at the antenna location. The entire unit goes up the mast in a waterproof enclosure. Power cable (not antenna cable) runs down the pole.
04
E860 DTU — Device Guide
The E860 DTU is a LoRa wireless I/O module. It has switch inputs (to read a float switch), relay outputs (to control a pump or contactor), and a built-in LoRa radio with SMA antenna connector.
Fig 4.1 — E860 DTU V1 device layout with animated LEDs
🔴 LED Indicators
Green POWER LED: Solid = device powered on
Orange RSSI LED: Blinking = LoRa signal active
Red OUT LED: On = relay output closed (active)
⚡ Power Supply
DC version: 8–28V DC on pins 15(+) and 16(−)
AC version: 85–265V AC on pins 15(N) and 16(L)
Check the label on your unit before wiring.
05
Wiring & Pinout Reference
The E860 has 32 terminal pins. Only a few are used in this installation. The highlighted rows below are the ones you will wire.
⚠️ Note: The Tambuki unit is a 2-port switch version. Switch input ports 3–8 are NOT available — do not wire to them.
Key Pins Used in This Installation
| Pin | Function | Used For | Suggested Wire |
|---|---|---|---|
| 1 | Switch Common | Float switch wire A (COM) | Black or Brown |
| 2 | Switch Input 1 | Float switch wire B (Signal) | Red or Orange |
| 3–10 | Switch Inputs 2–8 | NOT USED (2-port unit) | — |
| 11 | GND | Ground reference if needed | Green/Yellow |
| 12–13 | RS485 A/B | Not used in this job | — |
| 15 | DC V+ / AC N | Power supply positive | Red |
| 16 | DC V− / AC L | Power supply negative | Black |
| 17 | Relay 1 COM | Relay common (central site bridge) | Grey |
| 18 | Relay 1 NO | Relay normally-open (central bridge) | Grey |
| 19–32 | Relays 2–8 | NOT USED | — |
ℹ️ NO = Normally Open. The relay contact is OPEN when no signal received, and CLOSES when a LoRa signal activates it. This is the correct setting for pump control — pump is off by default.
06
Reservoir Site Setup
This is where the float switch is mounted in or on the water tank. The E860 here is configured as a MASTER — it reads the float switch and transmits to the central site when the tank is low.
Fig 6.1 — Reservoir site: float switch to E860 Master (animated water level)
🔴 WATERPROOF ENCLOSURE — MANDATORY: The E860 unit must be sealed inside a weatherproof (IP65 or better) enclosure mounted at the TOP of the mast, directly below the antenna. There is NO antenna extension cable — the magnetic base antenna sits on top of the enclosure lid. Power cable runs DOWN the pole to your supply. Float switch cable runs from the tank up to the enclosure.
Wiring Steps — Reservoir Site
1
Erect the mast — as high as possible (target 8m)Secure firmly. The enclosure with E860 mounts at the very top.
2
Mount IP65 weatherproof enclosure at mast topThe E860 lives inside this box. The lid must be flat metal so the magnetic antenna base sticks to it securely.
3
Mount magnetic base antenna on top of enclosure lid — perfectly verticalUse a spirit level. The antenna must point straight up. This is critical for range.
4
Run float switch cable from tank up the mast to the enclosureTwo wires only. Connect to Pin 1 (COM) and Pin 2 (IN1) inside the enclosure. Polarity does not matter.
5
Run power cable DOWN the mast from enclosure to power supplyConnect to Pin 15 (+) and Pin 16 (−). Use 12V or 24V DC stable supply. Cable must be weatherproofed where it enters the enclosure — use a waterproof cable gland.
6
Seal the enclosure and power onAll cable entries must use waterproof glands. Check: Green LED = solid. Orange RSSI = blinking when linked to Pakstoor.
07
Central Site Setup
The central site has two E860 units: a SLAVE (receives from reservoir) and a MASTER (transmits to borehole). They are hardwired together via the relay output of the SLAVE connected to the switch input of the MASTER.
Fig 7.1 — Central site: two E860 units hardwired relay-to-input (animated)
⚠️ Critical wiring: Slave Pin 17 (COM) → Master Pin 1 (COM). Slave Pin 18 (NO) → Master Pin 2 (IN1). This bridge passes the signal through.
🔴 PAKSTOOR MAST — WATERPROOF ENCLOSURE: Both E860 units are sealed in ONE IP65 enclosure at the top of the Pakstoor mast. Both magnetic antennas sit on the flat metal enclosure lid — perfectly vertical. Power cable runs DOWN the mast. Indicator lights run DOWN to ground level where they can be seen. The enclosure LEDs cannot be read from the ground — use the indicator lights instead.
Wiring Steps — Central (Pakstoor) Site
1
Erect the Pakstoor mast — as high as possible (target 15m)This must have clear line of sight to both reservoir and borehole. It is the highest point.
2
Mount one IP65 enclosure at the very top of the Pakstoor mastBoth E860 units (Slave + Master) go inside this single box. Lid must be flat metal for magnetic antennas.
3
Mount both magnetic antennas on the enclosure lid — both perfectly verticalSpace them at least 20cm apart. Use a spirit level on each. This is critical.
4
Wire the relay bridge inside the enclosureSlave Pin 17 (Relay COM) → Master Pin 1 (Switch COM)
Slave Pin 18 (Relay NO) → Master Pin 2 (Switch IN1)
Slave Pin 18 (Relay NO) → Master Pin 2 (Switch IN1)
5
Run indicator light cables DOWN the mast to ground levelWire indicator lamps from the relay outputs to where they can be seen — NOT read from the enclosure at the top. See Section 10 for wiring details.
6
Run power cable down the mast — power both E860 unitsEach E860 needs Pin 15 (+) and Pin 16 (−). Use waterproof glands at all cable entry points.
7
Seal enclosure and power onVerify via indicator lights at ground level — borehole light ON when pump running.
08
Borehole Site Setup
The borehole E860 is configured as a SLAVE. It receives the LoRa signal from the central site and its relay output drives the borehole pump contactor directly.
Fig 8.1 — Borehole site: E860 Slave fires contactor, pump runs (animated)
🔴 DANGER — Mains Voltage: The contactor handles mains electricity. Pump wiring MUST only be done by a qualified electrician. The E860 relay only triggers the contactor coil at low voltage — it must NEVER be wired directly to the pump motor.
⚠️ IMPORTANT — Two-stage contactor circuit: The E860 relay output is a small signal relay only. It must drive a proper borehole contactor (motor starter) — NEVER wire the pump motor directly to the E860 relay. The E860 relay energises the contactor coil (low current). The contactor then switches the pump motor (high current mains). These are two separate circuits.
🔴 WATERPROOF ENCLOSURE: E860 at borehole must also be in IP65 enclosure at mast top. Magnetic antenna on lid, perfectly vertical. Power cable down the mast. Only the relay output wires run to the contactor panel below.
Wiring Steps — Borehole Site
1
Erect the mast — as high as possible (target 8m)Point toward the Pakstoor mast. IP65 enclosure mounts at the top.
2
Mount IP65 enclosure with E860 at mast topMagnetic antenna on lid, perfectly vertical. Power cable and relay output cable run down the mast.
3
Run relay output cable from enclosure down to contactor panelE860 Pin 17 (COM) and Pin 18 (NO) — two wires only, low voltage. These connect to the contactor coil only.
4
Connect relay wires to borehole contactor coil (A1 and A2)E860 Pin 17 → Contactor coil A1
E860 Pin 18 → Contactor coil A2
This is low voltage only. The contactor coil draws minimal current.
E860 Pin 18 → Contactor coil A2
This is low voltage only. The contactor coil draws minimal current.
5
Qualified electrician completes mains wiring through contactorMains power in and pump motor out are wired through the contactor main contacts — completely separate from the E860 circuit.
6
Wire borehole ON/OFF indicator light from contactor auxiliary contactUse a contactor auxiliary contact (not the E860 relay) to drive the indicator light. See Section 10.
7
Power on E860 — verify via indicator lightIndicator light ON = pump running. Green LED inside enclosure visible through inspection window if fitted.
09
Remote IO Mode — How Inputs Mirror as Outputs
This is the core operating principle of the E860. Whatever the Master sees on its switch inputs, the Slave mirrors exactly on its relay outputs — over LoRa radio, wirelessly.
Fig 9.1 — Remote IO: float switch on Master mirrors as relay output on Slave (animated)
In plain language: Float switch low (tank empty) = Relay 1 on Slave closes = contactor fires = pump runs. Float switch high (tank full) = Relay 1 opens = pump stops.
10
Status Indicator Lights
Because the E860 units are sealed in weatherproof enclosures at the top of their masts, the onboard LEDs cannot be read from the ground. Indicator lights must be wired at ground level to show system status. Three indicator lights are recommended — one at each site.
ℹ️ Indicator light principle: Each light is driven by a relay output. The E860 relay closes when a signal is active — this powers the lamp. When signal stops, relay opens, lamp goes off. Use 12V DC lamps matched to your supply voltage.
Fig 10.1 — Remote Indicator: button presses on one unit light lamps on the other (animated)
⚠️ Borehole indicator — use contactor auxiliary contact: At the borehole site, the indicator light should be driven from an auxiliary contact on the borehole contactor (not from the E860 relay directly). This gives a true confirmation that the contactor and pump have actually fired, not just that the E860 relay closed.
Indicator Light Wiring Summary
| Site | Light Source | What It Shows | Wire From |
|---|---|---|---|
| Reservoir (Tambuki) | E860 Master — Relay OUT | Float switch LOW = tank needs water | Slave Pin 17 COM · Pin 18 NO → 12V lamp → GND |
| Central (Pakstoor) | E860 Master — Relay OUT | Signal being sent to borehole = pump commanded ON | Master Pin 17 COM · Pin 18 NO → 12V lamp → GND |
| Borehole | Contactor auxiliary contact | Contactor energised = pump actually running | Contactor AUX contact → 12V lamp → GND |
✅ Recommendation: Use green lamps for PUMP ON, red or amber for TANK LOW. Mount all indicator lights in a small weatherproof box at ground level at each site — easy to see without climbing the mast.
11
Testing & Fault Finding
System Test Procedure
1
Power on all three sitesStart borehole first, then central, then reservoir. Wait 30 seconds after each power-on for LoRa to link.
2
Check LEDs at each siteAll E860 units should show solid GREEN power LED and blinking ORANGE RSSI LED within 1 minute.
3
Simulate tank low — short Pin 1 to Pin 2 on reservoir E860Briefly connect a wire between Pin 1 and Pin 2. The chain should trigger: central relay clicks, borehole relay activates, contactor fires, pump starts.
4
Remove the wireFloat switch returns open. Chain reverses: relays open, contactor drops out, pump stops.
5
Check indicator light at central siteShould show ON when pump running, OFF when stopped.
LED Fault Guide
| Symptom | Likely Cause | Action |
|---|---|---|
| Green LED off | No power to E860 | Check pins 15 and 16 wiring. Check fuse/supply. |
| Orange RSSI not blinking | No LoRa signal | Check antenna connection. Check line of sight. Check other E860 is powered. |
| Relay not activating | Float switch not wired | Re-check pins 1 and 2. Test with wire short. |
| Pump not starting | Contactor coil not firing | Check relay pins 17/18 to contactor A1/A2. Check contactor itself. |
| Pump won't stop | Float switch stuck closed | Check float is free to rise. Check for debris in tank. |
| Intermittent operation | Weak LoRa signal | Increase antenna height. Remove obstructions between sites. |
✅ Already confirmed: LoRa point-to-point transmission between E860 devices has been tested and works. If radio issues appear after installation, check antennas and obstructions first.
12
Installation Checklist
Use this checklist on site. Tick each item before moving to the next site.
🌊 Reservoir Site
| ✓ | Task |
|---|---|
| ☐ | 8m mast erected and secured |
| ☐ | Antenna mounted at mast top, pointing toward central site |
| ☐ | Coax cable run from antenna down to E860 enclosure |
| ☐ | E860 mounted in weatherproof enclosure |
| ☐ | Float switch wired to Pin 1 (COM) and Pin 2 (IN1) |
| ☐ | Power supply connected to Pin 15 (+) and Pin 16 (−) |
| ☐ | Green LED solid on power-up |
| ☐ | Orange RSSI LED blinking (linked to central) |
📡 Central Site
| ✓ | Task |
|---|---|
| ☐ | 15m mast erected and secured |
| ☐ | Both antennas mounted at top of 15m mast |
| ☐ | Both coax cables run to enclosure |
| ☐ | Both E860 units mounted in weatherproof enclosure |
| ☐ | Slave relay Pin 17 → Master Pin 1 (hardwire bridge) |
| ☐ | Slave relay Pin 18 → Master Pin 2 (hardwire bridge) |
| ☐ | Indicator light wired to Master relay output (optional) |
| ☐ | Both units powered on Pin 15 and 16 |
| ☐ | Both green LEDs solid |
| ☐ | Both orange RSSI LEDs blinking |
⛏️ Borehole Site
| ✓ | Task |
|---|---|
| ☐ | 8m mast erected and secured |
| ☐ | Antenna mounted at top, pointing toward central site |
| ☐ | Coax cable run from antenna to E860 enclosure |
| ☐ | E860 mounted in weatherproof enclosure |
| ☐ | E860 Pin 17/18 wired to contactor coil A1/A2 |
| ☐ | Qualified electrician completed mains pump wiring |
| ☐ | Power supply connected to Pin 15/16 |
| ☐ | Green LED solid on power-up |
| ☐ | Orange RSSI LED blinking |
| ☐ | Full system test completed (simulated float switch) |
| ☐ | Pump starts and stops correctly |
ℹ️ This manual is hosted at: tambuki.cinnovate.co.za — Login:
deon / deonADDENDUM — NOT PART OF INSTALLATION MANUAL
E860-DTU V1 Technical Specification
Reference data for engineers and system designers. Ground-crew: refer to manual sections above.
A
E860-DTU V1 — Full Specification Sheet
Radio — LoRa
| Parameter | Value |
|---|---|
| Radio technology | LoRa (Long Range) |
| Frequency band | 433 MHz / 868 MHz / 915 MHz (region dependent) |
| Max transmission power | 20 dBm (100 mW) |
| Receiver sensitivity | −148 dBm |
| Typical open-air range | 3–8 km (terrain dependent) |
| Antenna connector | SMA female |
| Default antenna | Magnetic base omnidirectional, 3 dBi |
| Antenna impedance | 50 Ω |
| Communication mode | Point-to-point (P2P) or broadcast |
| Encryption | AES-128 |
| Air data rate | 0.3–62.5 kbps (LoRa SF7–SF12) |
Power Supply
| Parameter | DC Version | AC Version (A) |
|---|---|---|
| Input voltage | 8–28V DC | 85–265V AC |
| Power consumption | ≤ 3W idle, ≤ 5W TX | ≤ 3W idle, ≤ 5W TX |
| Supply terminals | Pin 15 (V+), Pin 16 (V−) | Pin 15 (N), Pin 16 (L) |
| Recommended supply | 12V DC regulated | 230V AC mains |
Operating Environment
| Parameter | Value |
|---|---|
| Operating temperature | −40°C to +85°C |
| Storage temperature | −40°C to +125°C |
| Humidity | 5–95% RH non-condensing |
| Enclosure (bare unit) | Not weatherproof — must be housed in IP65 enclosure |
| Recommended enclosure | IP65 or IP67 rated ABS or GRP enclosure |
Switch Inputs
| Parameter | Value |
|---|---|
| Number of inputs | 8 (Tambuki unit: 2 active) |
| Input type | Dry contact (volt-free) |
| Common terminal | Pin 1 (inputs 1–4), Pin 6 (inputs 5–8) |
| Input pins | Pins 2–5 (IN1–IN4), Pins 7–10 (IN5–IN8) |
| Activation | Short between COM and input pin |
| Max cable length | 500m (screened cable recommended) |
| Debounce time | ~20ms |
Relay Outputs
| Parameter | Value |
|---|---|
| Number of relays | 8 (Tambuki unit: 2 active) |
| Relay type | SPST Normally Open (NO) |
| Max switching voltage | 250V AC / 30V DC |
| Max switching current | 10A |
| Max switching power | 2500VA AC / 300W DC |
| Contact resistance | ≤ 100 mΩ |
| Relay 1 terminals | Pin 17 (COM), Pin 18 (NO) |
| Relay 2 terminals | Pin 19 (COM), Pin 20 (NO) |
| ⚠️ In this installation | E860 relay drives contactor coil ONLY — not pump directly |
RS485 / Serial
| Parameter | Value |
|---|---|
| Interface | RS485 half-duplex |
| Terminals | Pin 12 (A), Pin 13 (B) |
| Baud rate | 1200–115200 bps |
| Protocol | Modbus RTU compatible |
| Use in this installation | NOT USED |
Pin Reference — Complete Table
| Pin | Function | Notes |
|---|---|---|
| 1 | Switch Common (IN1–IN4) | COM for inputs 1 to 4 |
| 2 | Switch Input 1 | USED — Float switch |
| 3 | Switch Input 2 | Not active (2-port unit) |
| 4 | Switch Input 3 | Not active |
| 5 | Switch Input 4 | Not active |
| 6 | Switch Common (IN5–IN8) | COM for inputs 5 to 8 |
| 7–10 | Switch Inputs 5–8 | Not active |
| 11 | GND | Ground reference |
| 12 | RS485-A | Not used |
| 13 | RS485-B | Not used |
| 14 | PE | Protective earth |
| 15 | DC V+ / AC N | USED — Power positive/neutral |
| 16 | DC V− / AC L | USED — Power negative/live |
| 17 | Relay 1 COM | USED — Relay common |
| 18 | Relay 1 NO | USED — Relay normally open |
| 19 | Relay 2 COM | Not used |
| 20 | Relay 2 NO | Not used |
| 21–32 | Relays 3–8 COM/NO | Not used |
Tambuki System — Device Summary
| Unit | Site | Role | Inputs Used | Outputs Used |
|---|---|---|---|---|
| E860 #1 | Reservoir (Tambuki) | MASTER | Pin 1+2: Float switch | None (master transmits) |
| E860 #2 | Central (Pakstoor) | SLAVE | None (receives LoRa) | Pin 17+18: Bridge to E860 #3 |
| E860 #3 | Central (Pakstoor) | MASTER | Pin 1+2: From E860 #2 relay | Pin 17+18: Indicator lamp |
| E860 #4 | Borehole | SLAVE | None (receives LoRa) | Pin 17+18: Contactor coil A1/A2 |
ℹ️ Manufacturer: EBYTE (Chengdu Ebyte Electronic Technology Co. Ltd) · Model: E860-DTU(x0x0-400SL) · Protocol: LoRa proprietary P2P · Firmware: V1