PLC Field Notebook (formerly PLC IO Check) lets you quickly check and monitor the I/O status of Mitsubishi MELSEC PLCs in the field. Connect to the PLC directly over Ethernet from your phone : no PC or special hardware required : and read device values in real time.

■ Features
- IO Check : verify your registered X/Y I/O in the field as OK/NG (Manual, Auto, and Guided-sequence modes). Automatically flags cross-wiring and shorts, shows OK/NG badges in the list, and shares a CSV/summary report
- Direct MC Protocol / SLMP communication over Ethernet (TCP/UDP), 3E/4E Frame, Binary/ASCII
- ON/OFF monitoring of bit devices (X/Y/M/L/B)
- Word device values (D/W/ZR) : decimal/hex, signed/32-bit/float/string display
- Unlimited device registration, free monitoring activates up to the top 50 devices, auto-polling and manual refresh
- Auto-registration : create device sequences from a start address, step, and count
- Organize devices into collapsible hierarchical groups with drag-to-reorder, delete a whole group, and expand/collapse all groups at once
- Group/search/status filters, isolated error display
- Batch Monitor : enter devices and addresses directly to read multiple values in a table
- IO Grouping : quickly view device I/O on separate input and output signal cards
- Save, open, export, and share multiple projects as .plc files between devices
- Display languages : Korean, English, Japanese, Simplified Chinese, Traditional Chinese, and Vietnamese, with dark and light themes
- GX Works Import : open GX Works2 projects (.gxw) or comment/ladder CSV files, register new devices or merge comments, recover X/Y comments, group by device type or POU, preview the POU tree, and warn about duplicate coils
- Simple Logger : record events from direct BIT/WORD address conditions or periodic triggers and export recent logs to CSV. Pending records are recovered when you next open or start Simple Logger to prevent missing or duplicate entries
- Simple HMI : supports DISPLAY value, MOTION movement, and VISIBILITY bit bindings. Elements hide only when VISIBILITY is OFF and remain visible before data arrives, on read errors, or when monitoring stops
- In-app GX Works communication setup guide
- Calculators and tools : programmer calculator, electronic gear ratio, circumference, trigonometry, analog scaling, communication codes including checksum and CRC-16, serial transmission time, UVW stage alignment, ASCII table, and ASCII converter

※ Simple Logger entry, viewing, and recording plus core IO checking, monitoring, and calculators are free. One rewarded ad grants one token. One token is used only after a successful LOG/IO CSV save, GX Works new import/comment merge, or to hide bottom banners for 12 hours. Failed, cancelled, and no-op work is not charged. No in-app purchases or cash-equivalent rewards.

■ Supported
- MELSEC Q series (verified with QJ71E71-100 module and QnUDV built-in Ethernet)
- MELSEC iQ-R series (verified with RJ71EN71 module and built-in Ethernet)
- MC Protocol (SLMP) compatible Ethernet configurations

■ Safety
- This app is read-only (monitoring). It does not modify equipment.

This is a third-party utility for fast field I/O checks.

Disclaimer: This app is an independent third-party application and is NOT affiliated with, endorsed by, or approved by Mitsubishi Electric Corporation. "MELSEC", "GX Works" and related names are trademarks of their respective owners and are used here solely to indicate compatibility.

GX Works2 (.gxw) import is a compatibility convenience that extracts devices and comments from files you own. Results are for reference only : some devices or comments may be missing or interpreted differently, so always verify before field use. For complete, accurate data, exporting a comment CSV from GX Works2 is recommended. Password-protected (secured) files are not opened.

PLCManJP

Additional Information