PLC Expert by Max Meridian

Industrial Automation
Intelligence
On Demand

Fault code diagnosis, ladder logic assistance, network troubleshooting, drive configuration, and step-by-step repair procedures — for every major PLC platform. The knowledge base your maintenance team needs at 2am.

Try It Free See Pricing
Instant fault code lookup AI fallback for anything else No installation required Works on any device
PLC EXPERT — plc.maxmeridianai.com
3100
Q Series — Battery Low Warning
  • 1Replace with CPU POWERED ON — do not power off first or you will lose retentive memory
  • 2Battery type: Q6BAT (ER6V 3.6V lithium)
  • 3Clear error in GX Works2: Diagnostics → System Monitor
  • 4Take program backup immediately after replacement
Preventive schedule: Replace Q6BAT every 5 years. Error 3200 (battery voltage drop) means replace immediately — data loss risk is imminent.
Platform Support

Every Major PLC Platform

PLC Expert knows the specific fault codes, register addresses, wiring requirements, and software procedures for every major industrial automation platform.

PRIMARY SPECIALTY
Mitsubishi
Q Series · iQ-R · iQ-F (FX5)
FX3 · A Series · GOT2000 HMI
FR-A800 / FR-E800 Drives
CC-Link / CC-Link IE
Error code database (3000-4000 series)
GX Works2 / GX Works3 procedures
GOT HMI troubleshooting
CC-Link wiring & configuration
Modbus RTU / RS-485 setup
Battery replacement procedures
Program backup & restore
Device test & force outputs
Allen Bradley
ControlLogix · CompactLogix
MicroLogix · PLC-5
Studio 5000 / RSLogix
Fault code diagnosis
Tag-based programming help
EtherNet/IP troubleshooting
DeviceNet & ControlNet
Studio 5000 procedures
Siemens
S7-1500 · S7-1200
S7-300 · S7-400
TIA Portal / STEP 7
Diagnostic buffer reading
TIA Portal procedures
PROFIBUS & PROFINET
HMI (Comfort / Basic)
Safety PLC (F-CPU)
Omron
NX · NJ · CJ · CS
CP1H / CP1L
Sysmac Studio
Error code reference
EtherCAT troubleshooting
Sysmac Studio help
IO-Link configuration
Schneider
Modicon M340 · M580
Premium · Quantum
EcoStruxure
Unity Pro / Control Expert
Modbus TCP/IP setup
Fault diagnosis
Drives & HMI
Mitsubishi FR Series
AB PowerFlex · Yaskawa
Danfoss · Siemens G120
VFD fault code lookup
Parameter configuration
Modbus control setup
Wiring diagrams
Features

Built for the Maintenance Tech at 2am

When a machine is down and production is stopped, you need the right answer fast. PLC Expert gives it to you in seconds — not after a 20-minute search through a manual.

⚡
Instant Fault Code Lookup
Type any error code from any supported platform. Get the cause, severity, step-by-step fix, and what NOT to do — instantly from the built-in knowledge base, no API call needed.
FREE
⌨
Ask Anything
Anything not in the fault code database goes to AI — and gets a real, expert answer. Ask about ladder logic, wiring, parameter settings, software procedures, drive configuration, or anything else.
STANDARD
🔌
Network Troubleshooting
CC-Link, CC-Link IE, PROFIBUS, PROFINET, EtherNet/IP, Modbus RTU/TCP — wiring specs, termination requirements, IP configuration, and systematic diagnosis for communication faults.
STANDARD
📊
Drive & VFD Help
Fault codes, parameter setup, Modbus register addresses, wiring diagrams, and acceleration/deceleration tuning for Mitsubishi FR-A800/E800, Allen Bradley PowerFlex, and other major drives.
STANDARD
🖥
HMI Troubleshooting
GOT2000 communication errors, IP configuration, GT Designer3 procedures, and systematic diagnosis for HMI faults — step by step, no guessing.
STANDARD
🔧
Maintenance Procedures
Battery replacement, program backup and restore, online vs offline editing, forced output procedures, verify after download — all with the exact steps for your specific platform.
STANDARD
Pricing

One Hour of Downtime Pays for a Year.

At $500/hour machine downtime, PLC Expert pays for itself the first time it helps your tech find a fault in 5 minutes instead of 2 hours.

Free
$0 / forever
Instant fault code lookup for common platforms. No account needed.
  • Mitsubishi Q Series fault codes
  • Common error reference
  • Basic troubleshooting guides
  • AI-powered open Q&A
  • Network troubleshooting
  • Drive & HMI help
  • All platforms
Launch Free →
MOST POPULAR
Standard
$29 / seat / mo
Full AI-powered platform. Every platform, every question, answered.
  • Everything in Free
  • Unlimited AI Q&A
  • All PLC platforms
  • Network troubleshooting
  • Drive & VFD fault codes
  • HMI troubleshooting
  • Maintenance procedures
  • Ladder logic assistance
  • Wiring & configuration help
  • Parameter reference
Get Started →
Premium ★
$79 / seat / mo
For lead technicians and maintenance engineers managing multiple machines.
  • Everything in Standard
  • Fault history & job log
  • Save proven procedures
  • Custom knowledge base
  • Team training quizzes
  • Progress tracking
  • Machine monitoring
  • Multi-machine dashboard
Contact Sales →
Enterprise
from $999 / mo
Plant-wide deployment with machine monitoring and unlimited seats.
  • Everything in Premium
  • Unlimited seats
  • Machine monitoring dashboard
  • Alarm history by machine
  • OEE & downtime tracking
  • White label option
  • Admin console
  • Priority support
  • Custom onboarding
Contact Sales →

Want CNC Expert + PLC Expert together? See our Shop Bundles →

FAQ

Common Questions

How accurate are the fault code answers? ▶
The built-in Mitsubishi Q Series fault code database is verified against official Mitsubishi documentation — those answers are highly accurate. For other platforms and open-ended questions, the AI gives thorough answers based on deep training data but we always recommend verifying safety-critical procedures against your official documentation before performing electrical work.
Does it work for our older Mitsubishi A Series machines? ▶
Yes — the AI has knowledge of A Series PLCs including fault codes, GX Developer procedures, and common troubleshooting. The built-in RAG database is focused on Q Series, but the AI fallback covers A Series well for most common issues. If you have specific A Series machines we can add their fault codes to the built-in database on Enterprise plans.
Can our maintenance techs use it on their phones on the plant floor? ▶
Yes — PLC Expert is a web app that works in any browser on any device. No installation, no app store download. A maintenance tech can pull it up on their phone, type the fault code, and have the fix procedure in front of them in seconds — right at the machine.
Can we add our own procedures and fault codes? ▶
Yes — on Premium and Enterprise plans you can save your own proven procedures to the knowledge base. Enterprise plans also include the option to add machine-specific fault codes and procedures that are unique to your equipment. Contact us to discuss your specific needs.
Do you offer a free trial? ▶
Yes — email hello@maxmeridianai.com and we'll set you up with a 14-day Standard trial at no cost. No credit card required. We want you to see the value before you commit.

Put an Expert in Every Technician's Pocket

When a machine is down, every minute costs money. PLC Expert gives your team the answers they need — instantly, on any device, right at the machine.

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