WHEN THERE IS NO CONTROLLER TO TALK TO

The machine has no PLC. It still has signals.

Presses, converting lines, packaging machines, ovens, compressors and test rigs that predate the network — or that carry a PLC nobody is allowed to touch. You do not need a control retrofit to get data off them. You need to take the signal where it already exists.

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THE SITUATION

Three machines, three different reasons the protocol list does not help.

Every data project starts with a protocol question — FOCAS2, Modbus TCP, OPC UA, S7. That question assumes a controller exists, is on the network, and will answer. On a real floor, a meaningful share of machines fail at least one of those assumptions.

The machine has no PLC at all. It has an analog output card, a tacho, a proximity switch, a thermocouple, a pressure transducer. The signal is real and already wired. There is simply nothing on the machine that speaks a protocol.

The machine has a PLC you cannot modify. It is under OEM warranty, the program is know-how protected, or a download means stopping production. The controller is right there and effectively off limits.

The machine has a PLC with no network port — or one already consumed by an HMI, in a cabinet with no spare switch port and no cable run.

A protocol adapter cannot solve a problem that exists below the protocol layer.

HOW WE SOLVE IT

Take the signal where it already exists.

There are three honest routes, and which one applies is decided by what the machine physically offers — not by preference.

Analog or sensor signals, no PLC → mDAQ

  • Direct sensor acquisition. Four analog channels, 0–10 V or 4–20 mA, 16-bit, up to 860 S/s, capture pressure, flow, level, temperature and similar signals straight from the field.
  • Digital I/O alongside. Eight 24 V digital inputs and eight 24 V digital outputs for status, counts, alarms and enables.
  • No PLC in the loop. mDAQ removes the need for a standalone PLC when the job is sensor acquisition and publishing. It is an acquisition device — it does not replace a PLC's control, safety, sequencing or interlock functions.
  • Publishes on its own. HTTPS or MQTT over 4G, Wi-Fi or optional Ethernet, with GPS and an optional battery for sites without power or cable.

Run / stop and counts only → mTracker

  • Equipment-level digital signals. Run / stop, cycle and output-count signals wire straight to the unit — no manual production logs.
  • Reports OEE inputs. Production time, downtime, idle time and output quantity, plus location. EREMOS V2 computes the OEE from those inputs.
  • Built to retrofit. A miniature attachment with battery backup and cellular publish, for assets that shipped without telemetry — fixed or mobile.
  • Not an analog DAQ. If the signal you need is a 4-20 mA or 0-10 V measurement rather than a contact or pulse, mDAQ is the correct device.

A PLC you may read but not change → EdgeConnect

  • Read-only protocol access. Modbus TCP, Modbus RTU, OPC UA Client, Siemens S7, FOCAS2, MTConnect, Brother HTTP, EtherNet/IP, Mitsubishi MELSEC.
  • No program change where the controller already exposes the data — the usual blocker is access permission, not capability.
  • One canonical vocabulary across every machine, with store-and-forward and three-way diagnostics.

No cabinet PC, remote site → Edge Gateway

  • DIN-rail appliance. Embedded Linux, built-in Modbus TCP server/client, 4G / Wi-Fi / Ethernet, 24 V DC.
  • Removes the industrial PC for standalone Modbus TCP and cellular gateway use today.
  • Field-serviceable. Web-configurable, USB firmware updates.

Scoping note. Sensor type, loop power and signal conditioning per channel, channel counts, mounting, cable routing and site conditions are confirmed during BOM scope. Channel counts and ranges quoted here trace to the Elpis hardware ecosystem map and are confirmed at quoting time.

WHAT PLANTS ASK BEFORE SCOPING THIS

Questions a machine with no controller raises.

How do I collect data from a machine with no PLC?
Acquire the signal directly. An mDAQ reads the machine's existing sensor outputs — 0-10 V or 4-20 mA analog, plus 24 V digital inputs — with no PLC in the loop, and publishes over HTTPS or MQTT via 4G, Wi-Fi or Ethernet. You do not need to add a PLC in order to read sensors; a PLC is a control device, and acquisition alone does not require one.
Can I get OEE from a machine that only has an analog card?
Partly, and the distinction matters before you budget. An analog tap gives you a measurement — speed, pressure, temperature — and, where a pulse or contact exists, a count. It does not by itself give you job identity, good-versus-reject counts or stop reasons. If your OEE case rests on waste and changeover, confirm during scoping which of those signals the machine actually exposes, because the gap is in the machine, not in the acquisition device.
How do I get a 4-20 mA signal into MQTT?
Wire the loop into an mDAQ analog channel. It digitizes at 16-bit resolution, applies the engineering-unit conversion for that channel, and publishes over MQTT or HTTPS. Per-channel current-versus-voltage mode, loop power and signal conditioning are confirmed during BOM scope.
The machine has a PLC, but we are not allowed to modify the program. What now?
Two options, in order of preference. If the controller already exposes the values over a protocol and you can be granted read access, EdgeConnect reads them without any program change. If it does not, or access is refused, tap the equipment-level signals instead — run / stop, cycle and output counts into an mTracker, or analog measurements into an mDAQ. Neither touches the control program.
How many analog channels do I need per machine?
One mDAQ provides four analog channels and eight digital inputs. Whether one unit covers a machine depends on how many distinct measurements you need — a single machine-level speed or pressure reading is very different from per-station instrumentation. Count the signals you actually intend to act on before counting units; channel allocation is confirmed during BOM scope.
Does this work on a printing press, converting line or packaging machine?
The approach is machine-agnostic, because it depends on the signal rather than the machine type. Where a press or converting line exposes analog outputs or dry contacts, those are acquirable. Where the machine carries a richer production interface of its own — job and waste data from a press workflow system, for example — that interface will usually carry more context than an analog tap, and is worth establishing during scoping before hardware is quoted.
The machine is in a remote shed with no network and no spare power. Is that a blocker?
No. mDAQ and mTracker both publish over cellular and offer an optional battery or battery backup, buffering locally and publishing when connectivity returns. Supply range, battery runtime by reporting interval and antenna placement are confirmed during BOM scope.
Where does the data end up?
Field signals are acquired by mDAQ or mTracker and published over HTTPS or MQTT to EREMOS V2, which turns them into utilization, OEE, alarms and reports — with EdgeConnect optional in the path where a site also runs protocol-based sources and wants one canonical pipeline across all of them.
WHAT CHANGES

The machines that were invisible stop being invisible.

  • No control retrofit. The machine's control system is untouched — no program change, no download, no revalidation.
  • No PLC bought for acquisition. One device replaces a standalone PLC, a separate cellular modem and an edge appliance.
  • The old machines join the same report as the networked ones, instead of living in a spreadsheet beside it.
  • Signals you already paid for get used. The transducers and contacts are generally already fitted; nothing was reading them.

Outcomes depend on which signals a given machine exposes. Signal availability is established during scoping, before hardware is quoted.

TYPICAL ENGAGEMENT

How a no-controller machine typically gets scoped.

STEP 1

Signal survey per machine: what is physically available — analog outputs, dry contacts, pulses, existing transducers — and what each one actually represents.

STEP 2

Decide what you intend to act on. The measurement list drives channel counts and device selection, not the other way round.

STEP 3

BOM scope: device selection, per-channel sensor type and loop power, signal conditioning, mounting, power, connectivity and antenna placement.

STEP 4

Commission and verify against the machine's own behaviour, then publish into EREMOS V2 alongside the networked machines.

A signal survey is worth doing before any hardware is quoted. It is the step that most often changes the answer.

WHAT WE WILL NOT CLAIM

The limits, stated up front.

Acquisition is not control. mDAQ reads sensors; it does not replace a PLC's control, safety, sequencing or interlock functions, and we will not propose it as one.

A signal is not context. Analog and digital taps give measurements and counts. Job identity, reject classification and stop reasons come from a machine's own production interface where one exists — we will tell you which of those a given machine can and cannot provide.

Certification and ingress protection are scoped case by case. IP65 / IP67-compatible configurations can be scoped where a placement requires it. No formal certified rating is claimed.

RELATED

Looking for the same thing from another angle?

HARDWAREmDAQ — direct field acquisition, no PLC in the loop. HARDWAREmTracker — utilization and OEE inputs from equipment-level signals. SOLUTIONBrownfield modernization — when the controllers do exist, across five generations. PLATFORMEdgeConnect — the protocol-agnostic runtime for the machines that do answer.
START WITH THE SIGNAL SURVEY

Bring us the machine nobody can read.

Send the machine list with what each one physically exposes — or tell us you do not know yet, which is the more common starting point. The signal survey is the first deliverable either way.

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