Connecting WERMA Signal Towers

How to read machine states from WERMA signal towers with the Werma WIN Ethernet connector and map them into an ISA-95 style MQTT topic hierarchy.

This guide shows you how to read machine states from WERMA signal towers with the Connectware Werma WIN Ethernet connector and map them into an ISA-95 style MQTT topic hierarchy. A signal tower already shows the state of its machine on the shop floor, and the Werma WIN system makes exactly this state available for digital processing: a wireless transmitter on each tower reports the light states to a central Ethernet master. Because the state is taken from the tower itself, you get machine monitoring without touching the PLC or the machine control. The collected tier states are the typical input for andon boards, machine monitoring, and Overall Equipment Effectiveness (OEE) dashboards. In more detail, the following topics are covered:

• Understanding how the Werma WIN system provides machine states

• Finding the MAC addresses of the transmitters

• Creating the service commissioning file

• Mapping tower and tier states into an ISA-95 style MQTT topic hierarchy

• Turning the red tier into a machine-stop event with the Rule Engine

• Verifying data in the Data Explorer

A complete example file is available at the end of this guide.

Prerequisites

To follow this guide, you will need the following:

• A running instance of Cybus Connectware.

• A configured Werma WIN system: each signal tower is equipped with a WIN slave device (a wireless transmitter), the transmitters are associated with a Werma WIN Ethernet master, and the Ethernet port of the master is reachable from Connectware. The association between the Ethernet master and the transmitters is configured with the Windows-based Werma WIN software that is shipped with the hardware.

• The IP address, port, and password of the Werma WIN Ethernet master.

• Access to the Admin UI with sufficient user permissions.

• Basic knowledge of MQTT and the Connectware services concept (for example, service commissioning files, connections, and endpoints).

How the Werma WIN System Provides Machine States

The Werma WIN system consists of two kinds of devices. Each signal tower carries a WIN slave device, a wireless transmitter that monitors the switching state of the tower's tiers. The Werma WIN Ethernet master acts as the access point for this wireless network: it manages access to all associated transmitters, aggregates their data, and forwards it over Ethernet. Connectware connects to the Ethernet master with the Werma protocol and maps the proprietary Werma WIN protocol into MQTT/JSON. For the full system description, see the Werma WIN Ethernet connector reference.

Every transmitter provides the following data points:

• Tiers (t1, t2, t3, t4): the state of up to four digital switches, typically one per light tier of the tower. Each tier is on, off, or blink.

• RSSI: the signal strength of the wireless connection between the transmitter and the Ethernet master.

The WIN system sends state updates at fixed time intervals and whenever the state of any tier changes. You do not configure a polling interval; Connectware receives the updates as the WIN system sends them.

Which color a tier corresponds to depends on how the signal tower is assembled. In this guide, tier 1 (t1) is the red light. Check the tower assembly of your machines and adjust the tier selection accordingly.

A Werma WIN Ethernet master allows only one concurrent connection. If other applications, such as the Werma WIN Shop Floor Manager, need the data alongside Connectware, use the Connectware Werma Proxy Service to distribute the data to multiple applications simultaneously. See the Werma WIN Ethernet connector reference.

Finding the Transmitter MAC Addresses

Each transmitter is identified by its unique MAC address, for example 00BCDD. You can discover the MAC addresses of the associated transmitters in two ways:

• Inspect the Connectware logs after the connection to the Ethernet master is established.

• Use the Windows-based Werma WIN configuration software.

Write down which MAC address belongs to which machine. You will need one MAC address per signal tower in the service commissioning file.

Writing the Service Commissioning File

The service commissioning file contains all connection and mapping details. Do not worry about copying the snippets together into one file, the complete example file is available at the end of this guide. The example connects two signal towers, one on a milling machine and one on a lathe.

Description and Metadata

These sections contain general information about the service commissioning file. Only the metadata name is required.

description: >
  Service commissioning file that reads machine states from WERMA signal
  towers with the Werma WIN Ethernet connector and maps them into an ISA-95
  style MQTT topic hierarchy (Example)

metadata:
  name: WERMA Signal Towers Example
  provider: cybus
  homepage: https://www.cybus.io
  version: 1.0.0

Parameters and Definitions

We define the network address and the password of the Ethernet master as parameters, so you can set them when you install the service. The password has the factory default b1b0. The MAC addresses of the transmitters are parameters as well, so you can reuse the service for other machines.

The MQTT topics in this guide follow an ISA-95 style equipment hierarchy (<enterprise>/<site>/<area>/<line>). We define the prefix once in the definitions section and reuse it in every mapping with !sub.

parameters:
  wermaHost:
    description: Hostname or IP address of the Werma WIN Ethernet master
    type: string
    default: 192.168.1.100

  wermaPort:
    description: Port of the Werma WIN Ethernet master
    type: integer
    default: 15200

  wermaPassword:
    description: Password of the Werma WIN Ethernet master
    type: string
    default: b1b0

  millingMac:
    description: MAC address of the transmitter on the milling machine tower
    type: string
    default: 00BCDD

  latheMac:
    description: MAC address of the transmitter on the lathe tower
    type: string
    default: 00BCDE

definitions:
  MQTT_TOPIC_PREFIX: enterprise/hamburg/machining/line-1

Cybus::Connection

The connection resource establishes the connection to the Ethernet port of the Werma WIN Ethernet master. The optional connectionStrategy controls the retry behavior if a connection attempt fails. For all connection properties, see Werma WIN Ethernet Connection Properties.

resources:
  wermaConnection:
    type: Cybus::Connection
    properties:
      protocol: Werma
      targetState: connected
      connection:
        host: !ref wermaHost
        port: !ref wermaPort
        password: !ref wermaPassword
        connectionStrategy:
          initialDelay: 1000
          maxDelay: 10000
          incrementFactor: 2

Cybus::Endpoint

Each endpoint subscribes to one transmitter, identified by its MAC address. The field property selects which data point of the transmitter the endpoint carries:

Field	Data
t1, t2, t3, t4	The state of one tier: on, off, or blink
all	All tier states and the RSSI value in one object
rssi	The signal strength of the wireless connection
raw	Raw data as received from the Ethernet master

For all endpoint properties, see Werma WIN Ethernet Endpoint Properties.

This guide uses all for the complete tower state of each machine, t1 for the red tier of the milling machine, and rssi to monitor the wireless link quality:

millingTowerState:
  type: Cybus::Endpoint
  properties:
    protocol: Werma
    connection: !ref wermaConnection
    subscribe:
      mac: !ref millingMac
      field: all

millingRedTier:
  type: Cybus::Endpoint
  properties:
    protocol: Werma
    connection: !ref wermaConnection
    subscribe:
      mac: !ref millingMac
      field: t1

millingRssi:
  type: Cybus::Endpoint
  properties:
    protocol: Werma
    connection: !ref wermaConnection
    subscribe:
      mac: !ref millingMac
      field: rssi

latheTowerState:
  type: Cybus::Endpoint
  properties:
    protocol: Werma
    connection: !ref wermaConnection
    subscribe:
      mac: !ref latheMac
      field: all

Cybus::Mapping

The mapping publishes each endpoint on a topic of the ISA-95 hierarchy.

mapping:
  type: Cybus::Mapping
  properties:
    mappings:
      - subscribe:
          endpoint: !ref millingTowerState
        publish:
          topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/state'
      - subscribe:
          endpoint: !ref millingRedTier
        publish:
          topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/red'
      - subscribe:
          endpoint: !ref millingRssi
        publish:
          topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/rssi'
      - subscribe:
          endpoint: !ref latheTowerState
        publish:
          topic: !sub '${MQTT_TOPIC_PREFIX}/lathe-01/tower/state'

With this mapping, the complete tower state of the milling machine is published on the topic enterprise/hamburg/machining/line-1/milling-01/tower/state, and every other endpoint follows the same pattern.

Turning the Red Tier into a Machine-Stop Event

The topics so far carry states. Downstream consumers such as andon boards or alerting systems often want events instead: one message at the moment a machine stops. You can derive this event from the red tier with two data processing rules in an additional mapping:

• The cov rule (change of value) only forwards a message when the tier state differs from the previous one. This suppresses the periodic updates that the WIN system sends while the state is unchanged.

• The filter rule discards every message whose JSONata expression evaluates to a falsy value. The expression value = 'on' only lets messages pass in which the red tier is switched on.

- subscribe:
    endpoint: !ref millingRedTier
  publish:
    topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/events/machine-stop'
  rules:
    - cov:
        key: value
    - filter:
        expression: value = 'on'

The combination publishes exactly one message on enterprise/hamburg/machining/line-1/milling-01/events/machine-stop at the moment the red light switches on. If a blinking red light also counts as a stop on your shop floor, extend the expression to value = 'on' or value = 'blink'.

Installing the Service Commissioning File

1. Install the service commissioning file. See Installing Services.

2. Enable the service. See Enabling Services.

Result: The service is enabled. Connectware connects to the Werma WIN Ethernet master and starts receiving state updates from the configured transmitters.

Verifying the Data

Open the Data Explorer and subscribe to enterprise/hamburg/machining/line-1/#. The tower/state topics carry a JSON object with all tier states and the RSSI value:

{
  "timestamp": 1784194200354,
  "value": {
    "t1": "off",
    "t2": "off",
    "t3": "on",
    "t4": "off",
    "rssi": 63
  }
}

The single-tier topic tower/red carries the state of the red tier alone:

{
  "timestamp": 1784194200354,
  "value": "off"
}

A few plausibility checks for the first readings:

• The tier states on the tower/state topics match the lights you see on the towers.

• When a tier changes on the machine, the update appears on the topic within a few seconds.

• The tower/rssi value is a number and stays in a similar range over time. A sudden drop indicates a problem with the wireless link between the transmitter and the Ethernet master.

• The events/machine-stop topic stays silent until the red light switches on, and then carries exactly one message.

If the connection does not reach the Connected state, verify that the IP address, port, and password match the Ethernet master and that the port is reachable from Connectware. Also make sure that no other application is connected to the Ethernet master, for example the Werma WIN configuration software or the Werma WIN Shop Floor Manager, because the Ethernet master allows only one concurrent connection. If the connection is established but a tower publishes no data, check the MAC address of its transmitter in the Connectware logs or in the Werma WIN configuration software, and verify that the transmitter is associated with the Ethernet master you are connected to.

Service Commissioning File Example

werma-signal-towers-example.yml

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werma-signal-towers-example.yml

---
# ----------------------------------------------------------------------------
# Service Commissioning File
# ----------------------------------------------------------------------------
# Copyright: Cybus GmbH
# Contact: [e-mail]
# ----------------------------------------------------------------------------
# Connecting WERMA Signal Towers (Example)
# ----------------------------------------------------------------------------

description: >
  Service commissioning file that reads machine states from WERMA signal
  towers with the Werma WIN Ethernet connector and maps them into an ISA-95
  style MQTT topic hierarchy (Example)

metadata:
  name: WERMA Signal Towers Example
  provider: cybus
  homepage: https://www.cybus.io
  version: 1.0.0

parameters:
  wermaHost:
    description: Hostname or IP address of the Werma WIN Ethernet master
    type: string
    default: 192.168.1.100

  wermaPort:
    description: Port of the Werma WIN Ethernet master
    type: integer
    default: 15200

  wermaPassword:
    description: Password of the Werma WIN Ethernet master
    type: string
    default: b1b0

  millingMac:
    description: MAC address of the transmitter on the milling machine tower
    type: string
    default: 00BCDD

  latheMac:
    description: MAC address of the transmitter on the lathe tower
    type: string
    default: 00BCDE

definitions:
  # ISA-95 style topic prefix: <enterprise>/<site>/<area>/<line>
  MQTT_TOPIC_PREFIX: enterprise/hamburg/machining/line-1

resources:
  # Connection to the Werma WIN Ethernet master
  wermaConnection:
    type: Cybus::Connection
    properties:
      protocol: Werma
      targetState: connected
      connection:
        host: !ref wermaHost
        port: !ref wermaPort
        password: !ref wermaPassword
        connectionStrategy:
          initialDelay: 1000
          maxDelay: 10000
          incrementFactor: 2

  # All data points of the milling machine tower: tiers t1-t4 and RSSI
  millingTowerState:
    type: Cybus::Endpoint
    properties:
      protocol: Werma
      connection: !ref wermaConnection
      subscribe:
        mac: !ref millingMac
        field: all

  # Red tier of the milling machine tower (tier 1 in this example)
  millingRedTier:
    type: Cybus::Endpoint
    properties:
      protocol: Werma
      connection: !ref wermaConnection
      subscribe:
        mac: !ref millingMac
        field: t1

  # Wireless signal strength of the milling machine transmitter
  millingRssi:
    type: Cybus::Endpoint
    properties:
      protocol: Werma
      connection: !ref wermaConnection
      subscribe:
        mac: !ref millingMac
        field: rssi

  # All data points of the lathe tower
  latheTowerState:
    type: Cybus::Endpoint
    properties:
      protocol: Werma
      connection: !ref wermaConnection
      subscribe:
        mac: !ref latheMac
        field: all

  mapping:
    type: Cybus::Mapping
    properties:
      mappings:
        - subscribe:
            endpoint: !ref millingTowerState
          publish:
            topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/state'
        - subscribe:
            endpoint: !ref millingRedTier
          publish:
            topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/red'
        - subscribe:
            endpoint: !ref millingRssi
          publish:
            topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/tower/rssi'
        - subscribe:
            endpoint: !ref latheTowerState
          publish:
            topic: !sub '${MQTT_TOPIC_PREFIX}/lathe-01/tower/state'
        # Machine-stop event: only forward when the red tier switches to 'on'
        - subscribe:
            endpoint: !ref millingRedTier
          publish:
            topic: !sub '${MQTT_TOPIC_PREFIX}/milling-01/events/machine-stop'
          rules:
            - cov:
                key: value
            - filter:
                expression: value = 'on'

Disclaimer: WERMA and WERMA WIN are trademarks of WERMA Signaltechnik GmbH + Co. KG.