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The “unusual” protocols in SMT/electronics plants — and how Ignition connects them

Solutions / Advisory · ~7 min read · Updated 2026

An SMT / electronics assembly plant has its own “protocol ecosystem”, quite different from a typical process plant: pick-and-place machines, reflow ovens, AOI, solder-paste printers… talk to each other and to the MES via SECS/GEM, IPC-CFX, IPC-Hermes, SMEMA. Every machine vendor does it differently → integration gets messy. Ignition (Inductive Automation) is the platform that ties it all into one — SCADA/MES/UNS.

Two axes in a nutshell: Horizontal (M2M) = machine ↔ adjacent machine on the line (board transfer, handshake) → SMEMA (legacy) / IPC-Hermes-9852 (modern). Vertical = machine ↔ MES/host (data reporting, control) → SECS/GEM, IPC-CFX. Confusing these two axes causes most integration headaches.

The protocols, one by one

  1. SECS/GEM (SEMI, since the 80s–90s) — the machine ↔ host standard from semiconductors, also widely used in SMT. Modern equipment runs HSMS (SECS over TCP/IP) instead of SECS-I (RS-232). GEM = a standard equipment behavior model (states, alarms, recipes, data collection).
  2. IPC-CFX (Connected Factory Exchange) — an OPEN IPC standard (2018), “plug-and-play” for electronics assembly. Transport over AMQP 1.0 + JSON encoding, via a pub/sub broker; covers both M2M and machine↔MES. The most modern direction.
  3. IPC-Hermes-9852 (The Hermes Standard) — handshake & board transfer machine ↔ machine on the SMT line, over TCP/IP + XML. Replaces SMEMA, carrying board data (barcode, orientation) not just signals. CFX integrates bi-directionally with Hermes.
  4. SMEMA (IPC-SMEMA-9851) — the legacy electrical/digital I/O handshake between conveyor machines (board ready / machine ready). Simple, signal-only, no data — still very common on older lines.
  5. IPC-CAMX — the older XML-based predecessor to CFX (legacy, fading). MQTT/Sparkplug B — IIoT pub/sub, the core of a UNS. OPC UA — the common standard, the most universal bridge.

Is your SMT line a “tower of Babel”?

Send: your machine list + which protocol each supports (SECS/GEM, CFX, Hermes, SMEMA…), and your goal (OEE, traceability, MES). Get an architecture proposal to unify on Ignition.

How Ignition ties these together

  1. OPC UA (native) Ignition is a built-in OPC UA client/server → connects anything speaking OPC UA. Many SMT machines/PLCs already expose OPC UA.
  2. MQTT / Sparkplug B (a strength) Via the Cirrus Link modules, Ignition is the #1 platform for MQTT/Sparkplug → build a UNS, unifying line data into one namespace.
  3. IPC-CFX (AMQP) Ignition consumes AMQP via Python scripting (an AMQP library) or an AMQP ↔ MQTT bridge → mapping CFX messages into tags/UNS.
  4. SECS/GEM Via a SECS/GEM ↔ OPC UA gateway or a third-party SECS/GEM module for Ignition → Ignition reads the semiconductor/SMT equipment's states/alarms/recipes.
  5. Hermes / SMEMA Hermes: open a TCP socket + parse XML in Ignition scripting. SMEMA: read the digital signals via PLC/IO into Ignition → monitor handshakes & line blocking.
  6. Roll up into MES/OEE/traceability Once machine data is in Ignition: build OEE, downtime, board traceability by barcode, line dashboards — all on one platform.
Direction tip: new machines supporting CFX → prefer CFX (open, data-rich). Machines with only SECS/GEM → via an OPC UA gateway. Old lines with only SMEMA → read via PLC/IO. Funnel everything into a UNS over MQTT/Sparkplug to unify — this is where Ignition shines most.

How DeepDebug helps

We advise the SMT line connectivity architecture (choosing CFX/SECS-GEM/Hermes/SMEMA per machine) + build the bridges into Ignition (OPC UA, MQTT/Sparkplug, AMQP, scripting) → one clean UNS/MES.

Book an SMT ↔ Ignition connectivity consult

Per-machine protocol assessment + a roadmap to unify on Ignition/UNS.