Schneider TSX47 series PLC selection

Schneider TSX47 series PLC selection

In the 1990s to early 21st century, Telemecanique's TSX 47 series programmable controller (now a brand under Schneider Electric) became the core control equipment for many production lines in industries such as automotive, packaging, and material conveying, thanks to its modular structure, rich I/O interfaces, and simple PL7-2 graphical programming environment. Although the series has long been discontinued, there are still a large number of devices in operation worldwide. When PLC malfunctions or requires expansion of functions, engineers often face difficulties such as difficulty in finding spare parts, confusion of models, and unclear alternative solutions. This article is based on the official data manual of the TSX 47 series, systematically reviewing the hardware architecture, memory capacity, expansion capability, and selection considerations of the five major models (TSX 47-J, 47-10, 47-20J, 47-20, 47-25), and proposing an upgrade and replacement approach for modern control systems, providing practical reference for engineers maintaining old production lines.

Overview and Model Classification of TSX 47 Series

The TSX 47 series belongs to the modular sequential PLC (Sequential PLC), which adopts a rack mounted structure and all discrete I/O interfaces are universal. According to the body size and functional positioning, this series is divided into two physical formats: short rack and standard rack:

Short rack: Provides 5 available slots for compact configurations, represented by models TSX 47-J and TSX 47-20J.

Standard rack: Provides 8 available slots for larger I/O requirements, represented by models TSX 47-10, TSX 47-20, and TSX 47-25.

All basic configurations can add up to 8 additional slots through direct I/O expansion racks (TSX RKE 7/8), bringing the total number of slots to 16, significantly expanding the system's I/O capacity. The following table summarizes the core differences of each model:

Model Rack Format Available Slot Maximum Discrete I/O Points Intelligent Module Supports Direct Expansion

TSX 47-J Short 5 160 0 None

TSX 47-20J Short 5 160 2 (inside the base frame) None

TSX 47-10 standard 8 256 0 available (1)

TSX 47-20 standard 8 256 2 (inside the base frame) has (1)

TSX 47-25 standard 8 256 4 (inside the base frame) has (1)

Among them, TSX 47-25 is the flagship model in the series, which not only supports up to 4 intelligent modules, but also comes standard with a 32K byte RAM user memory card and UNI-TELWAY network module (TSX SCM 2116), suitable for complex applications that require fieldbus communication.

Hardware composition and selection key points

2.1 Rack and Power Supply

The basic configuration rack (short or standard) integrates the following components:

Power module: optional 110/240V AC 50/60Hz (TSX SUP 40, TSX 47-25 uses TSX SUP 702) or 24/48V DC (TSX SUP 41/42). According to the on-site power supply conditions, please note that the 24V DC version is suitable for DC power supply environments such as ships and mobile devices.

Processor (CPU): Built in 2K byte battery backed up RAM data storage for storing application data (bit objects and word objects). The front of the processor is equipped with a green RUN indicator light and three red fault indicators (CPU fault, memory card fault, I/O fault).

User memory card slot: used to insert removable program memory (RAM or EPROM).

9-pin SUB-D connector: used to connect programming terminals (20mA current loop).

Direct expansion connector: limited to TSX 47-10/20/25, used for connecting expansion racks.

Selection points: If the system only needs to control a small amount of I/O and has no expansion requirements, TSX 47-J or 47-20J can meet the requirements; If there may be a need to increase the number of I/O points in the future, priority should be given to the standard rack model (47-10/20/25); If intelligent modules (such as counting, analog, axis control, communication, etc.) are required, 47-20J, 47-20, or 47-25 must be selected.

2.2 User Memory Card Selection

The user program (PL7-2 logic) and constants are stored in separate replaceable memory cards, with a fixed constant area of 2K bytes. The optional capacity is 8K, 16K, or 32K bytes, divided into two technical types:

Battery backup RAM card (TSX RAM 8/16/32): Backup time of 5 weeks, suitable for debugging stages with frequent program modifications and situations where volatile data needs to be maintained.

EPROM card (TSX RPM 8/16/32): UV erased read-only memory, data permanently saved, suitable for finalized programs to prevent accidental modifications.

Engineering suggestion: Use RAM cards during the development phase and EPROM cards after batch curing. If you need to update the program on site, you can prepare a pre programmed EPROM to replace it directly.

2.3 Compatibility limitations of discrete I/O interfaces

The TSX 47 series supports multiple discrete I/O modules with 4/8/16/24/32 points. However, it should be noted that the 24 point and 32 point modules can only be installed on the base frame (main frame). When using these high-density modules, the corresponding slots on the direct expansion rack must be left blank (no modules can be installed). This limitation stems from bus bandwidth and addressing design, which engineers must adhere to when planning I/O layouts, otherwise it may lead to address conflicts or communication anomalies.

2.4 Intelligent modules and special functions

The TSX 47-20J/20/25 supports the installation of intelligent modules in the first few slots of the base frame, and the specific supported quantities are shown in the table. Common intelligent modules include:

Counting modules: TSX CCM 100, TSX DTM 100, TSX DMR 1652

Analog input/output: TSX AEM 41 (measurement system), TSX ASR 40 (analog output)

Axis control: TSX DTM 100, etc. (only supported by TSX 47-20/25)

Asynchronous serial link: TSX SCM 20/22 (except TSX SCM 13)

UNI-TELWAY bus module: TSX SCM 2116 (standard on TSX 47-25, optional for other models)

TELWAY Network: TSX MPT 104 (up to one can be installed in any slot)

Note that TSX 47-10 and 47-J do not support any intelligent modules and can only use discrete I/O.

Memory Structure and Software Environment

3.1 Internal RAM Data Storage

The 2K byte battery backup RAM built into the CPU is used to store application data and is divided into a bit storage area and a word storage area.

The bit memory contains the following objects:

Number of object types

System position 24

Function block output bit 128

Discrete I/O image 256 (TSX 47-10/20) or 160 (TSX 47-J/20J)

Internal bit 256

Grafcet step 96

1 fault position per I/O module

16 bit word memory:

Number of object types

Internal word 1024 (the first 128 words can be directly addressed, and the rest are transmitted through a table)

Grafcet Step Activity Time 96

Intelligent module word (TSX 47-20J/20/25 only) 2 × 16

System Word 4

TELWAY Network Public Character 16 × 4

Attention: The battery backup period is 5 weeks. If there is a long-term power outage, it is necessary to ensure that the battery is in good condition. It is recommended to keep the PLC powered when replacing the battery to avoid data loss.

3.2 Programming Software and Languages

The TSX 47 series uses PL7-2 graphical programming software and supports two IEC standard languages:

Ladder diagram: suitable for discrete logic control, following the convention of relay control.

Grafcet (Sequential Function Diagram): Designed specifically for sequential control, it can visually express process steps and transfer conditions.

PL7-2 provides both application development and diagnostic functions, and can be connected to a programmer or PC via a 9-pin terminal interface (20mA current loop) (adapter conversion to RS232 is required).

Directly expand the rack and wiring

4.1 Expansion Rack Components

The direct expansion rack is used to increase the number of I/O slots in the system, which includes:

An empty rack (all unused slots are equipped with dust covers)

A 1.2-meter-long extension cable

Expansion racks also offer short or standard formats:

TSX RKE 7: Short rack, 7 available slots

TSX RKE 8: Standard rack, 8 available slots

The expansion cable must be securely locked onto the dedicated connectors of the base frame and expansion rack. The maximum length of the cable is 1.2 meters and cannot be extended on its own, otherwise it may cause signal attenuation and communication errors.

4.2 Installation precautions

All slots are equipped with positioning devices (TSX RAC 40) and backplane connector covers to prevent module misplacement.

Empty slots must be sealed with dust covers (TSX RAC 50) to maintain IP20 protection level.

Grounding strips (TSX RAC 20/25) must be installed, especially when using TSX BLK 4 terminal blocks, to ensure reliable grounding of the system.

Module extraction requires the use of a specialized extraction tool (TSX MNC 30), and direct manual extraction is strictly prohibited to avoid damaging the circuit board.

Environmental specifications and electrical characteristics

5.1 Environmental conditions

Parameter Range

Working temperature+5 ° C~+55 ° C

Storage temperature -25 ° C~+70 ° C

Altitude 0~2000m

Protection level IP20 (compliant with IEC 664 and NF C 20040)

IP20 means that it can only prevent solid foreign objects with a diameter greater than 12.5mm from entering and is not waterproof. Therefore, PLC should be installed in a dry and dust-free control cabinet.

5.2 Power supply selection

Select power module based on on-site power supply type:

Communication version: rated 110/220V AC, 50/60Hz (TSX SUP 40, TSX SUP 702 required for TSX 47-25). Suitable for standard industrial power grids.

DC version: rated 24V DC or 48V DC (TSX SUP 41/42). Suitable for DC systems such as automobiles and ships, or for situations backed up by batteries.

Attention: The DC power supply must be stable, with ripple less than 5%, and a fuse or circuit breaker must be installed at the input end.

Maintenance and Upgrade Strategy for Old Production Lines

6.1 Spare parts procurement channels

Due to the complete discontinuation of the TSX 47 series, the original spare parts inventory is extremely low. Engineers can obtain it through the following channels:

Professional second-hand automation equipment suppliers (such as Artisan Technology Group, etc.) provide refurbished modules that have passed testing and come with warranty.

Auction websites or idle industrial trading platforms, but with high risks, require confirmation of module functionality.

Third party repair services can perform chip level repairs on damaged CPUs, power supplies, or I/O modules.

Attention: When purchasing, it is necessary to check the model suffix (such as TSX 47-10 with 110/220V version, 24V version, 48V version, order numbers TSX 47 1001, TSX 47 1011, TSX 47 1021 respectively) to avoid voltage discrepancies.

6.2 Program Backup and Migration

If the original PLC can still run, immediately use PL7-2 software to upload the program through the terminal port and save it as PG or ZAP file. For models that use EPROM cards, a programmer can be used to read the contents of the EPROM and save it as a binary file.

If the program is lost and cannot be recovered, the only way is to rewrite it based on the on-site device action logic, which usually requires a lot of time and downtime losses. Therefore, regular backup is the key to maintaining the lifeline of old production lines.

6.3 Upgrade alternative solutions

When TSX 47 series PLC faults cannot be repaired or modern communication functions (such as Ethernet, OPC UA) need to be added, upgrading to Schneider Electric's current mainstream Modicon series controllers should be considered:

Modicon M221: Logic controller, suitable to replace TSX 47-J/10, supports Ethernet and CANopen, programming software is SoMachine Basic (ladder diagram similar to PL7-2, learning curve smooth).

Modicon M241/M251: Stronger performance, supports pulse output and motion control, can replace TSX 47-20/25, supports Ethernet/IP, Modbus TCP, programmed with EcoStruxure Machine Expert.

Modicon M580: High end PAC, suitable for large-scale systems, can retain the original I/O lines but require replacement of all modules.

When upgrading, due to the incompatibility of TSX 47 series I/O modules (such as TSX DExxxx) with Modicon's new rack, it is generally recommended to replace the rack, power supply, and all I/O modules as a whole, leaving only the on-site wiring terminals. In terms of programming, the PL7-2 ladder diagram can be manually converted into a Modicon ladder diagram or structured text. For projects using Grafcet, SFC language can be used in the new platform.

Common faults and rapid diagnosis

7.1 CPU red LED indicator

There are three red LEDs on the front of the processor:

Method for handling the meaning of LED identification

CPU processor failure attempts to restart PLC; If it is constantly on, the CPU needs to be replaced

MEM memory card malfunction. Re plug or replace the memory card and check if the card is inserted incorrectly

I/O fault check to see if unsupported modules are inserted (such as 24/32 point modules in the expansion shelf); Check module address conflicts

7.2 Program not running

Possible reasons for the green RUN light not turning on:

The user's memory card is empty or there is a program error. Download the program again using PL7-2 software.

System configuration error (such as hardware configuration not matching actual slot). Enter the programming software to perform "configuration" and "generation" operations.

Battery depletion leads to RAM data loss. Replace the battery and download the program again.

7.3 I/O module unresponsive

Check if the module is securely inserted into the rack and if the positioning device is stuck.

Check the power supply of the module (some modules require external 24V).

Check the fault indicator lights on the module (if any). Some models (such as the TSX DMX series) come with LED display channels for channel status.

Confirm the address allocation of the module: The TSX 47 series adopts automatic addressing, but the I/O addresses on the expansion rack will be postponed from the base frame address. I/O mapping table can be viewed through programming software.

7.4 Expansion Rack Communication Interruption

Check if the expansion cable is reliably connected and if there is any looseness or oxidation at both ends.

Confirm if the power supply of the expansion rack is normal (the expansion rack requires independent power supply and cannot be powered from the base frame).

Confirm that the expansion connector of the base frame is not damaged; Some older connector pins are prone to bending.