OMRON SYSMAC CS Series CS1G/H-CPU  H Programmable Controller

OMRON CS1-H Series Programmable Controllers: Architecture, Functionality, and Version Evolution

1.Positioning and Core Advantages of CS1-H CPU Unit

The OMRON CS series PLC is a high-performance controller designed specifically to meet the needs of medium to large-scale industrial control. This series maintains compatibility with traditional PLCs such as the C200H series while providing faster processing speed, larger storage capacity, and richer features. The CS1-H CPU unit is a high-performance model in this series, designed to achieve faster cycle times, more efficient structured programming, and more flexible network communication.

According to the manual description, the basic instruction processing time of CS1-H CPU unit is as low as 0.02 microseconds, and the special instruction processing time is as low as 0.06 microseconds. Its program capacity can reach up to 250K steps, data memory (DM+EM) can reach up to 448K words, and it can support up to 5120 I/O points. These fundamental performance indicators enable it to handle complex logic control, process control, and data intensive applications.

2. Unit version: Refined control of functional evolution

The introduction of the concept of "unit version" in the CS1-H CPU unit is the first key feature emphasized in the manual. This mechanism enables OMRON to add new features through firmware or microcode upgrades without changing the hardware. Users can identify the feature set supported by the CPU unit based on the version number on the product label (such as Ver.2.0, Ver.3.0, Ver.4.0, Ver.4.1). Units without version number markings are called "Pre Ver." versions.

Unit version recognition: Users can confirm the unit version through the "PLC Information" or "Unit Manufacturing Information" function of CX Programmer software (Ver. 4.0 and above), or by directly viewing the nameplate on the front of the CPU unit.

Version and Function Support Matrix: The manual provides a detailed list of the functions supported by different versions, clearly demonstrating the evolution path of the product.

Ver. 2.0 and later: Introduced many practical features, such as:

Single task upload/download: allows multiple developers to work in parallel, only transferring modified tasks to improve team development efficiency.

Enhanced read protection password: can set read protection for the entire UM (user program memory) or specific tasks, and can prohibit program backup OBJ files have strengthened intellectual property protection.

FINS write protection: FINS write commands sent to CPU units through networks such as Ethernet can be restricted, allowing writes from specific nodes and enhancing network security.

Online network connection without I/O table: Even without creating an I/O table, CX Programmer can directly connect to PLC through Ethernet or other networks, simplifying initial setup.

Supports 8-level network communication: FINS commands can traverse up to 8 network levels, greatly expanding the scope of remote monitoring and programming.

Multiple new application commands: including multi interlock commands (MILH/MILR/MILC), time proportional output (TPO), gray code conversion (GRY), and combination commands that interact with external devices such as numeric keyboards and 7-segment code displays.

Ver. 3.0 and later: Function blocks become core upgrades.

Function Block: Compliant with IEC 61131-3 standard, allowing users to encapsulate standard processing flows into reusable modules, supporting ladder diagrams and structured text programming, greatly improving the reusability and maintainability of the program.

Serial gateway: The built-in serial port (RS-232C/peripheral port) of the CPU unit can automatically convert received FINS commands into CompoWay/F commands, enabling transparent access of network devices to OMRON components on the serial line.

Annotation memory: A dedicated area is opened in the internal flash memory of the CPU unit for storing symbol tables, annotations, and program index files, without relying on storage cards or EM file memory.

Ver. 4.0 and later: Enhanced the flexibility and application scope of functional blocks.

Function block online editing: allows modification of function block definitions during PLC operation, greatly reducing debugging and maintenance time.

Function block input-output variables: Breaking through the previous limit of up to 4 characters for data transmission, supporting the transmission of large amounts of data such as tables.

Text string support in function blocks: Strings can be directly processed in structured text, simplifying programming for communication commands and data display.

Ver.4.1 and beyond: Security has been further enhanced.

Read protection with extended password: Provides stronger encryption for UM and task read protection.

Disable password input after five consecutive password errors: effectively prevents brute force cracking attempts.

Use production batch number protection program to run: The program can be bound to a specific production batch number CPU unit to run.

3. System architecture and configuration capability

The CS1-H CPU unit has high system scalability and can build control systems ranging from small to medium to large.

Rack and Expansion:

CPU rack: composed of CPU unit, power supply unit, and CPU backplane.

Expansion rack: Up to 7 expansion racks (CS series expansion rack or C200H expansion I/O rack) can be connected, and the total cable length must not exceed 12 meters. The CS series long-distance expansion rack can be configured into two series, each with a maximum length of 50 meters and a total length of 100 meters.

SYSMAC BUS Slave Rack: Used to build remote I/O systems, each master unit can connect up to 8 slave racks.

Unit type and I/O allocation:

Basic I/O units: including input, output, and hybrid I/O units of CS series and C200H series. Its I/O memory (CIO 0000- CIO 0319) is allocated in the order of its installation position (slot) on the rack. Users can set the first address of each rack or slot through CX Programmer to achieve flexible I/O address planning.

Special I/O units: including specialized functional units such as analog, temperature control, position control, and high-speed counting. Each unit is assigned 10 words in the CIO 2000-CIO 2959 area based on its unit number (0-95), and 100 words in the DM area (D20000-D29599) for parameter settings.

CPU bus unit: including network communication units such as Controller Link, Ethernet, DeviceNet, etc. Each unit is assigned 25 words in the CIO 1500-CIO 1899 area based on its unit number (0-15), and 100 words for parameter settings in the DM area (D30000-D31599).

4. Memory architecture and data processing

The memory of CS1-H CPU unit is divided into I/O storage area and parameter area, with clear structure and clear functions.

I/O storage area:

CIO area: the core area used for exchanging data with various units, and unused parts can be used as internal workstations.

Workspace (W): dedicated bits and words for internal programming, not assigned to external I/O, and is the preferred workspace for programming.

Retention zone (H): Content retention during power failure or mode switching, commonly used to store critical states or set values.

Auxiliary area (A): Contains a large number of read-only and read-write system flags and control bits, such as cycle time, error flags, clock data, operation start/end time, etc. For example, A000 is a read-only free running timer that increments every 10ms.

Data Memory (DM): A general-purpose data area for reading and writing 16 bit data in word units, with power-off holding.

Extended Data Storage (EM): Similar in function to DM, but divided into multiple 32K word "banks", with a maximum of 13 banks (0 to C). Part of the EM area can be configured as file memory.

Index registers (IR0-IR15): 32-bit registers used to store PLC memory addresses and achieve indirect addressing. Supports automatic addition, subtraction, and offset, making it a powerful tool for handling table data and loops.

Data Register (DR0-DR15): A 16 bit register used to provide offset for index registers.

Parameter area:

PLC settings: including core operating parameters such as CPU unit startup, communication ports, cycle time, interrupt tasks, etc.

Register I/O table: records the actual installed unit model and location, and compares it with the actual configuration when the CPU starts up.

Routing table: used to define the transmission path of FINS commands in a multi-layer network.

5. Core functions and programming features

Task programming: The program can be divided into up to 32 loop tasks and 256 interrupt tasks (power off interrupt, scheduled interrupt, I/O interrupt, external interrupt). Task Control Instructions (TKON/TKOF) can dynamically enable or disable loop tasks, achieving program modularization and optimizing loop time.

Function block: Supports ladder diagrams and structured text (ST), allowing for code encapsulation and reuse. The impact of instantiation on loop time can be calculated as: startup time+I/O parameter transfer processing time+execution time of defined instructions.

Instruction set: It has about 400 instructions, including text string processing, table data processing, floating-point operations, high-speed counters, positioning control, and other advanced instructions.

Communication function:

Built in ports: one peripheral port and one RS-232C port, supporting Host Link, NT Link (1: N), no protocol, serial gateway (CompoWay/F) and other modes.

Protocol macro: Through the serial communication board/unit, users can define the protocol for communication with third-party serial devices, and execute PMCR instructions to complete data exchange.

Network communication: FINS message communication, data linking, and remote I/O control are achieved through network units such as Ethernet, Controller Link, and DeviceNet.

6. Operation and maintenance

DIP switch: There is an 8-bit DIP switch under the front cover of the CPU unit, which is used to set write protection, automatic program transfer at startup, peripheral port/RS232C communication mode, etc.

PLC settings: Configure through CX Programmer or programming console, including startup mode, I/O response time, watchdog timer, fixed cycle time, serial port parameters, etc.

Backup: User program and parameter area data will be automatically backed up to the built-in flash memory of the CPU unit. The simple backup function can backup all data (programs, parameters, I/O memory, specific unit/board data) to the storage card by pressing the power switch of the storage card.

Fault diagnosis: The system records up to 20 errors (including user-defined FAL/FALS errors) in the error log (A100-A199), including error codes and occurrence times. The auxiliary area provides rich status indicators for diagnosis.

7. Security and Compliance

The manual prominently emphasizes safety precautions, including:

External safety circuit: Emergency stop, interlock, limit and other safety measures must be implemented in the PLC external circuit.

Output failure protection: Considering that the output unit may remain ON due to relay fusion or transistor damage, the external circuit design must be able to cope with such risks.

Battery error handling: The data in the DM, EM, and HR areas are backed up by the battery, and the user program should monitor the battery error flag (A40204) and take measures when the voltage is low.

EC Directive Compliance: The CS series PLC complies with EMC Directive and Low Voltage Directive, but needs to be installed in the control cabinet and appropriate noise suppression measures taken.