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WelcoYour alerts, by text.

PLC alarm SMS without a modem in the control panel

PLC alarm SMS works without a modem in the panel. Once your HMI, SCADA, a gateway or a plant app emails the fault, Welco turns it into one short text. When a turning machine stops on third shift with a broken tool, the tech on call reads the machine and the fault in plain words. No SIM card in the cabinet.

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  • No SIM or modem in the panel
  • No change to PLC logic needed
  • No per-user fees

Works by email with

  • PLC alarms
  • Ignition
  • GE iFIX

Setup guide for

  • FactoryTalk

A PLC chassis with a power supply, CPU and four I/O modules: input I:3/5 from pressure switch LT-07 chatters, the channel faults, the slot 3 FAULT LED blinks and the CPU passes the alarm to PLANT. The email reaches Welco and the phone shows: “Welco: [LT-07] STOPPED, load monitor tool broken at 6:12 AM. Reply STOP to opt out.”

Animation: a long Machine PLC alert email is trimmed into one short text: "Welco: [LT-07] STOPPED, load monitor tool broken at 6:12 AM. Reply STOP to opt out."

What the tech on call gets from PLC alarm texts

  • The machine and the fault in words

    The text says LT-07 stopped, tool broken. Bit names and part counts stay in the email.

  • Only the tech who can fix it

    A rule reads the machine or cell name and texts that area's tech, not the whole plant.

  • No SIM card in the cabinet

    Texts come from Welco's alert numbers, so no panel needs a cellular plan of its own.

  • A chattering sensor stays quiet

    When a loose sensor sets and clears a bit all night, flood control caps the texts while you fix the logic.

How a PLC fault becomes an email

A programmable logic controller (PLC) is the small industrial computer that runs a machine, a pump or a line. It knows the moment a motor trips. Most PLCs don't send email on their own, so something next to them does.

  • The HMI or SCADA. The screen or server that reads the PLC sends an alarm email, as with FactoryTalk line alarms. This is the most common path. See the SCADA systems Welco covers.
  • The PLC itself. Some controllers and panel HMIs have an email function you can call from logic when a bit turns on.
  • A gateway or RTU. A cellular or network box reads PLC tags and emails on a change.
  • A plant app or database job. A small service watches tags or a SQL table and emails when a row says ALARM.

Set up PLC alarm SMS in 4 steps

These steps assume one of the email paths above is working, or can be added by your controls team. The full SCADA setup guide goes deeper.

  1. Pick the alarms that deserve a text

    Choose faults that stop production or risk damage: motor overload, e-stop, low oil, high temperature, loss of air. Leave operator prompts and counters on the HMI.

  2. Approve the sender and invite your techs

    In Welco, add the address that sends the alarm email to the senders Welco trusts. Invite each tech by email. They join with their own mobile and reply YES.

  3. Point the alarm email at your Welco address

    In the HMI, gateway or app, add your Welco address as a recipient. Put the machine name and the fault at the start of the message.

  4. Trip a test fault on an idle machine

    Force a harmless alarm bit and check the text. Welco test mode shows the result in the feed without sending.

Send your next machine fault to a phone

Point the PLC alarm email at Welco and invite the tech on call.

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing

Text me my PLC alarmsBook a demo

A hot press on third shift

One fault, routed to the one person who can fix it.

  1. The plant app emails the press fault

    PRESS-04 ALARM Status RUNNING/WARN ALARM_H; Hydraulic oil temp 62 C

  2. A rule picks the mechanic, not the electrician

    The machine name matches the press cell, and hydraulic faults go to the on-call mechanic.

  3. The mechanic sees the press and the temperature

    Welco: [Press 4] Hydraulic oil temp HIGH, 62 C at 2:30 AM. Reply STOP to opt out.

  4. A quick reply to the shift lead

    Checking the oil cooler fan. 20 min

  5. The maintenance mailbox gets the note

    Welco emails replies to the alarm's sender. Forward a no-reply sender to the maintenance inbox.

    Reply from the on-call mechanic: Checking the oil cooler fan. 20 min

  6. The fault is reset at the HMI

    The press alarm is cleared at the machine, as always. A text reply never resets anything.

Times are an example. Text delivery depends on mobile networks.

Other PLC alarm texts

Masked examples of controller faults that factories and packaging lines send to a phone. A one-text trim rule shapes each one.

  • Extruder: Welco: [Extruder 2] Barrel zone 3 heater FAULT at 12:52 AM. Reply STOP to opt out.
  • Air: Welco: [Compressor Room] Header pressure LOW, 78 psi at 5:17 AM. Reply STOP to opt out.
  • Robot cell: Welco: [Robot Cell 3] Safety gate OPEN, cell stopped at 1:44 AM. Reply STOP to opt out.

A phone showing these alert texts: Extruder, "Welco: [Extruder 2] Barrel zone 3 heater FAULT at 12:52 AM. Reply STOP to opt out."; Air, "Welco: [Compressor Room] Header pressure LOW, 78 psi at 5:17 AM. Reply STOP to opt out."; Robot cell, "Welco: [Robot Cell 3] Safety gate OPEN, cell stopped at 1:44 AM. Reply STOP to opt out."

Getting the right tech, not the whole plant

PLC alarms are specific. Use that to text only the person who can fix it.

  • By machine or cell

    An alert rule can match the machine name and send the text to that cell's tech.

  • By shift

    On-call routing sends third-shift faults to the on-call tech and day faults to the area lead.

  • When a fault chatters

    Add a delay or latch in the logic first, so one fault sends one email. Flood limits protect the phone in the meantime.

Frequently asked questions

Do I still need a GSM modem or SIM card on the PLC?

Not for Welco. The texts come from Welco's alert numbers, so no SIM sits in the panel and no cellular plan is needed for alarms. What you need instead is a path for the fault to become an email, such as the HMI, a gateway or a plant app.

Does Welco connect to our PLCs or the controls network?

No. Welco has no route to a controller and never reads a tag. It receives the email after your HMI, gateway or app sends it out through your mail server.

Which PLC alarms should I text?

Text faults that need a person soon: line stops, motor trips, e-stops, high temperature, low pressure and loss of utilities. Keep quality warnings, counts and operator prompts on the HMI. Too many texts teach techs to ignore them, so start small and add alarms after a week.

Can a tech reset or acknowledge the fault by replying?

No. The reply is emailed to the alarm's sender so people can see who is on it. Faults are still reset at the machine or the HMI.

Can one email include several alarm bits?

Yes. Some plant apps send one email listing every active bit, like ALARM_A and ALARM_C, and Welco sends it as one text. A rule can cut the list to the first line or swap codes for words. The tech then reads tool broken, not a bit number.

What does it cost to text PLC alarms?

No per-user, hardware or setup fees apply, so every tech can join. Each short alarm uses one message credit for each phone it reaches. Plans are on the pricing page.

Send controller faults to the tech who can fix them

Point your PLC alarm email at Welco and test it on an idle machine.

Text me my PLC alarmsBook a demo

7-day free trial, 15 message creditsCard required for verificationNo charge for 7 daysEmail reminder before billing