Delta PLC Addressing Guide: Understanding X, Y, M, D, T, C, and S Device Types
Published on Jun 2, 2025 | Category: ispsoftin a industial automation by plc addrssing of device like input putput memory,latch relay etc are very imortant. Each device is assigned an address using specific device types like X, Y, M, D, and others, followed by a numeric identifier (e.g., X0, Y1, M100, D0). These addresses can store and represent different types of data, such as bits, bytes, words, integers, or strings.device address represent physical input output device, internal memory, timer counter, consatant value etc. addressing is essential for accurate logic execution in automation systems.In this article, we provide a complete guide to Delta PLC addressing. You’ll learn how to use X, Y, M, D, T, C, and S device types in ISPSoft, along with practical ladder logic examples to help you apply this knowledge in real-world projects.
What Are Device Addresses in Delta PLC?
In Delta PLCs, device addresses define where and what type of data is stored in the system. They act as memory references that hold specific data types—such as Boolean (bit), integer, or word values. These addresses are essential for organizing logic in PLC programming and directly impact the accuracy and reliability of automation processes.
Correct and efficient use of device addresses ensures smooth data handling, logical operations, and proper control of physical and internal components.
Device addresses are categorized by type, each representing a specific function within the PLC system:
- X – Represents physical input devices, such as sensors and pushbuttons.
- Y – Represents physical output devices, like relays, lamps, and actuators.
- M – Represents internal memory bits used for logic control and temporary flags.
- T – Represents timers used to generate time delays in the program.
- C – Represents counters for counting operations or events.
- D – Represents data registers for storing numerical values or constants.
- S – Represents stepping relays, used as state flags for steps in sequential control.
- Link Register – Used for data exchange between PLC and external devices or internal modules.
- HC (High-speed Counter Bit) – A 32-bit counter that can also be used as a bit device.
- E (Word Offset Modifier) – Used to modify the word offset of a device dynamically.
- SM (Special Auxiliary Relay) – Bit device used as a state flag for special system functions.
- SR (Special Data Register) – Word device used to store system-level or special function data.
By understanding and correctly applying these device types and their address ranges, you can create powerful and flexible automation logic using Delta PLCs and ISPSoft.
Delta PLC Input (X) and Output (Y) Addressing
In Delta PLCs, X and Y represent physical input and output devices respectively. Inputs typically include devices like sensors and pushbuttons, while outputs control devices such as relays, lamps, and actuators. The addressing format and range for X and Y devices depend on the PLC model and CPU series. Delta’s AH series supports both bit-type and word-type addressing for flexible automation control.
Address Ranges by PLC Series
- ES, EX, SS, SA, SX, SC Series
- X (Input Relays): Address range from X0 to X177
- Y (Output Relays): Address range from Y0 to Y177
- EH2/SV, EH3/SV2, ES2, EX2 Series
- X (Input Relays): Address range from X0 to X377
- Y (Output Relays): Address range from Y0 to Y377
- SS2, SA2, SX2, SE Series
- X (Input Relays): Address range from X0 to X377
- Y (Output Relays): Address range from Y0 to Y377
AH Series PLC input X and Y Addressing (Bit and Word Type)
In the AH series, input and output devices can be addressed using both bit and word formats. The available address range expands with higher-end CPU modules.
- AHCPU500 – Basic CPU Module
- input realy X (Bit type): X0.0 to X63.15
- output realy Y (Bit type): Y0.0 to Y63.15
- input realy X (WORD type): X0 to X63
- output real Y (Word type): Y0 to Y63
- AHCPU510 / AHCPU501 – Basic CPU Modules
- input realy X (Bit type): X0.0 to X127.15
- output realy Y (Bit type): Y0.0 to Y127.15
- input realy X (WORD type): X0 to X127
- output real Y (Word type): Y0 to Y127
- AHCPU520 / AHCPU511 – Basic CPU Modules
- input realy X (Bit type): X0.0 to X255.15
- output realy Y (Bit type): Y0.0 to Y255.15
- input realy X (WORD type): X0 to X255
- output real Y (Word type): Y0 to Y255
- AHCPU530 / AHCPU521 – Basic CPU Modules
- input realy X (Bit type): X0.0 to X511.15
- input realy Y (Bit type): Y0.0 to Y511.15
- output real X (Word type): X0 to X511
- output real Y (Word type): Y0 to Y511
- AHCPU531 – Basic CPU Module
- input realy X (Bit type): X0.0 to X1023.15
- input realy Y (Bit type): Y0.0 to Y1023.15
- output real X (Word type): X0 to X1023
- output real Y (Word type): Y0 to Y1023
Data Registers (D) in Delta PLC
Mitsubishi Data Registers Devices (D) are used to stored numerical (decimal) value. it represented as D0, D1 etc. these devices used for arithmetic instruction, analog signal instruction. a value that the program writes to a data register remain unchanged until the program overwrites it with another value. data register is availavel as latched and no latched. following are the example range of data register in delta plc for more details of range please read manual properly.
- ES/EX/SS Series:
- D0 to D599 – General Data Registers
- D1000 to D1311 – Special Data Registers
- SA/SX/SC Series:
- D0 to D9999 – General Data Registers
- D1000 to D1999 – Special Data Registers
- EH2/SV, EH3/SV2, ES2, EX2, SS2, SA2, SX2, SE Series:
- D0 to D11999 – General Data Registers
- D1000 to D1999 – Special Function Registers
- D9800 to D9999 – Module-Specific Registers
AH series plc data register have two type bit types as well as word type. foolowing are the range for bit type and word type data register in delta plc.
- AH500 Basic CPU Modules:
- AHCPU500: Word addressing from D0 to D16383, Bit addressing from D0.0 to D16383.15
- AHCPU510: Word addressing from D0 to D32767, Bit addressing from D0.0 to D32767.15
- AHCPU520 / AHCPU530: Word addressing from D0 to D65535, Bit addressing from D0.0 to D65535.15
- AH500 Advanced CPU Modules:
- AHCPU501: Word addressing from D0 to D24575, Bit addressing from D0.0 to D24575.15
- AHCPU511: Word addressing from D0 to D49151, Bit addressing from D0.0 to D49151.15
- AHCPU521: Word addressing from D0 to D98303, Bit addressing from D0.0 to D98303.15
- AHCPU531: Word addressing from D0 to D131071, Bit addressing from D0.0 to D131071.15
Delta PLC Counter (C) Addresses and Ranges
In Delta PLCs, counters are identified by the prefix C followed by a number (e.g., C0, C1, etc.). They are used to count pulses or events and support both 16-bit and 32-bit modes. The number of available counters and their type varies based on the PLC model.
Counter Types
- 16-bit Up Counters: Standard counters used for counting rising edge signals.
- 32-bit High-Speed Counters: Used for high-frequency pulse counting with faster scan cycles.
Counter Address Ranges by PLC Series
- ES/EX/SS Series MPU:
- 16-bit Up Counters: C0 to C111 – General-purpose
- 16-bit Latched Counters: C112 to C127 – Retain value after power-off
- 32-bit High-Speed Latched Counters:
- 1-phase, 1-input: C235 to C238, C241, C242, C244
- 1-phase, 2-input: C246, C247, C249
- 2-phase, 2-input: C251, C252, C254
- SA/SX/SC Series:
- C0 to C255 – General-purpose and high-speed 16/32-bit counters
- EH2/SV, EH3/SV2, ES2, EX2, SS2, SA2, SX2, SE Series:
- C0 to C254 – Full support for standard and high-speed counter operations
- AH500 Series CPU Modules:
- Basic CPUs (AHCPU500/510/520/530): C0 to C2047
- Advanced CPUs (AHCPU501/511/521/531): C0 to C2047
Note: High-speed counters (HC0 ~ HC63) are available in both basic and advanced AH series models for pulse frequencies that exceed standard counter capabilities. Always consult the specific hardware manual for exact configuration and limitations.
Delta PLC Timer Addresses (T) and Ranges
In Delta PLCs, timers are identified by the prefix T followed by a number (e.g., T0, T1, etc.). These devices are used for time delay operations in ladder logic and support multiple resolutions including 100 ms, 10 ms, and 1 ms. The available timer types and ranges depend on the PLC model and CPU series.
Timer Address Ranges by PLC Series
- ES/EX/SS Series MPU: (Total: 128 timers)
- T0 to T63 – 100 ms general-purpose timers
- T64 to T126 – 10 ms general-purpose timers
Note: M1028 = ON for 10 ms mode, OFF for 100 ms mode - T127 – 1 ms general-purpose timer
- SA/SX/SC Series MPU: (Total: 256 timers)
- T0 to T191 – 100 ms general-purpose timers
- T192 to T199 – 100 ms subroutine timers (non-latched)
- T200 to T239 – 10 ms general-purpose timers (non-latched)
- T240 to T245 – 10 ms accumulative timers (latched)
- T246 to T249 – 1 ms accumulative timers (latched)
- T250 to T255 – 100 ms accumulative timers (latched)
- EH2/SV, EH3/SV2 Series MPU: (Total: 256 timers)
- T0 to T191 – 100 ms general-purpose timers (latching configurable via parameters)
- T192 to T199 – 100 ms subroutine timers
- T200 to T239 – 10 ms general-purpose timers (latching configurable via parameters)
- T240 to T245 – 10 ms accumulative timers (latched)
- T246 to T249 – 1 ms accumulative timers (latched)
- T250 to T255 – 100 ms accumulative timers (latched)
- AH500 Series CPU Modules:
- All models: T0 to T2047 – General-purpose and high-resolution timers
Note: Timer base resolution and latched behavior may be affected by model-specific settings and configuration flags. Refer to the respective CPU manual for detailed timer usage and memory mapping.
Delta PLC Auxiliary Relay (M) Addresses and Ranges
In Delta PLCs, auxiliary relays are represented by the letter M followed by a number (e.g., M0, M1000, etc.). These internal relays are used for internal control logic, flags, temporary storage, and system-level functions. Delta PLCs categorize M relays into three types: general-purpose, latched, and special-purpose relays. Below is a breakdown of M address ranges by series:
Auxiliary Relay (M) Address Ranges by PLC Series
- ES/EX/SS Series:
- General-purpose: M0 to M511 and M768 to M999
- Latched: M512 to M767
- Special-purpose: M1000 to M1279
- EH2/SV Series:
- General-purpose: M0 to M499
- Latched: M500 to M999 and M2000 to M4095
- Special-purpose: M1000 to M1999
- ES2/EX2 Series:
- General-purpose: M0 to M511, M768 to M999, M2000 to M2047
- Latched: M512 to M767 and M2048 to M4095
- Special-purpose: M1000 to M1999
- SS2 Series:
- General-purpose: M0 to M511
- Latched: M512 to M999 and M2000 to M4095
- Special-purpose: M1000 to M1999
- AH500 Series CPU Modules:
- All models: M0 to M8191 – Includes both general-purpose and latched auxiliary relays