Table of Contents
- Overview
-
Hardware Limits & Recommendations
- Analog Inputs
- Optically‑Isolated Digital Inputs
- Power Options & PoE
-
Wiring Examples
- Current Transducer → Analog Input
- Green Stack Light → Analog Input
- Chuck Open Contact → Opto Input
- Adapter Script Templates
- Troubleshooting Checklist
- Key Specs
Overview
The Sealevel 170PoE is a compact, Ethernet-based analog input module that provides remote data acquisition over Modbus TCP. Powered via PoE, it offers eight 12-bit analog inputs and is ideal for industrial monitoring and control applications.
Sealevel adapter scripts are written in YAML and form the bridge between physical hardware (eI/O modules) and the MachineMetrics platform. This guide focuses on the eI/O‑170 family and adds practical engineering limits, wiring best practices, and concise examples you can copy‑paste into your own scripts.
Quick‑Start: Jump straight to the wiring examples if you already know the basics.
Hardware Limits & Recommendations
Analog Inputs
| Feature | Spec | Notes |
| Channels | 8 single‑ended or 4 differential | Software‑selectable |
| Ranges | 0‑5 V, 0‑10 V, ±5 V, ±10 V | Never exceed ±10 V at the pin—there is no over‑voltage clamp. |
| Resolution | 12‑bit (≈2.44 mV @ ±5 V) | ~0.024% of full scale |
| Input impedance | 100 kΩ | Safe to wire in parallel with most sensors |
Best practices
- Scale any 4‑20 mA loops with a precision 250 Ω resistor (1%, 0.25 W) to create a 1‑5 V span in the 0‑5 V range.
- To maximize resolution, pick the smallest range that envelopes your signal.
- Leave a small head‑room (≈5 %) under 5 V or 10 V to avoid clipping during transients.
- Shielded twisted‑pair recommended for runs >3 ft; tie shield to earth at one end only.
Optically‑Isolated Digital Inputs
| Feature | Spec | Practical Tip |
| Type | Dry‑contact sensing | Module sources 12 mA through 330 Ω resistor |
| Isolation | 1 kV DC to logic ground | Safe for most CNC common I/O voltages |
| Activation | Short to Common (no external V+ needed) | Ideal for relay, prox sensor, or bare contacts |
Best practices
- Use a relay (form‑A reed is fine) when tapping into PLC points >30 V or when potential transients exist.
- For proximity sensors that provide NPN open‑collector outputs, tie the collector to the input and emitter to common.
- Avoid directly driving the opto input with external supply; it adds ground loops and wastes the built‑in current source.
Power Options & PoE
| Mode | Requirement | Recommendation |
| DC Jack | 9‑30 V DC @ ≤5 W | Use 24 V industrial DIN PoE injector supply when PoE not available |
| PoE | IEEE 802.3af‑2003, Class 0, ≤3.5 W | A PoE‑Plus (802.3at) switch is preferred when powering >10 devices on the same switch budget |
Tips
- Keep CAT‑5e/6 cables <100 m and shielded if running inside panels with VFD noise.
- For tight cabinets, a mid‑span PoE injector avoids rewiring the switch.
- Budget ~7 W per port on the PoE switch to be safe (switches round up power classes).
Wiring Examples
Current Transducer → Analog Input 1
- If your transducer outputs 4‑20 mA, place a 250 Ω resistor across pin 1‑9 and set range to 0‑5 V.
- Keep analog pair separate from motor leads; twists at least 4 turns/ft.
Green Stack Light → OPTO Input 1
Barfeeder Contact → OPTO Input 2
- If the machine contact switches a higher voltage or unknown source, interpose a reed relay: coil on machine side, contacts wired as above.
- Opto inputs are polarity‑agnostic—either pin can be common.
Adapter Script Templates
Template 1 – Current Transducer + Execution State
version: 2
unit-id: 1
registers:
analog_in0:
address: 0
func: 4
type: int16
coils:
chuck_open:
address: 0
func: 2
part_count_input:
address: 1
func: 2
variables:
# 0‑10 V TO kW (example scaling)
spindle_power_kw:
- source: analog_in0 / 409.6 * 5 # 0‑10V to 0‑5kW
execution:
- source: spindle_power_kw > 2.0
- state:
- ACTIVE: this
- READY: true
chuck_state:
- source: chuck_open
- state:
- OPEN: this
- CLOSED: true
part_count:
- source: part_count_input
- rising-edge
- count
data-items:
- execution
- part_count
- chuck_stateTemplate 2 – Part Counter with Relay Isolation
version: 2
unit-id: 1
coils:
part_sensor:
address: 1
func: 2
variables:
part-count:
- source: part_sensor
- rising-edge
- count
speed_ppm:
- source: part-count
- window-count: 60
data-items:
- part-count
- speed_ppmTemplate 3 - Only using Opto Inputs (Dry contacts)
version: 2
unit-id: 1
coils:
run_signal:
address: 0
func: 2
part_sensor:
address: 1
func: 2
variables:
part-count:
- source: part_sensor
- rising-edge
- count
execution:
- source: run_signal
- state:
- ACTIVE: this
- READY: true
data-items:
- part-count
- execution
Troubleshooting Checklist
- Analog reads zero ➜ Check range, loose common, or sensor supply.
- Opto input stuck ON ➜ Measure contact for leakage (<1 mA). Add relay isolation.
- No PoE ➜ Verify port delivers ~48 V under load; CAT‑5e pinout correct.
-
Script won’t load ➜ Validate YAML, ensure
version: 2and correct indent.
Appendix A – Key Specs
eI/O‑170 (excerpt)
- Analog Inputs: 8 SE / 4 DIFF, ±10 V max, 12‑bit, 100 kΩ
- Opto Inputs: 2 × dry‑contact, 12 mA source, 1 kV isolation
- Relay Outputs: 2 × SPST solid‑state, 60 V DC @ 2.5 A max
- Power: 9‑30 V DC (≤5 W) or PoE 802.3af‑2003 Class 0 (≤3.5 W)
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