PACFramework

PACFramework > 1. Core Concepts

1.5 Recommendations for Naming PACFramework Components and Elements

Naming Structure Elements

• Bit names within structures must be unique at the same nesting level. For example, if a structure has a field named VAL, the set of bit fields must not include the name VAL. This ensures consistent end-to-end naming.
• Prefixes:
  • Time-related variable attributes should begin with the prefix T_, for example, T_STEP1, T_PREV.

Naming Process Variables (LVL1)

Process variables should preferably follow a three-level naming convention:

UNIT_INSTRUMENT_SIGNAL

• UNIT: the name of the plant, location, or equipment unit, needed for identifying automation means across different equipment groups.
• INSTRUMENT: identification of automation means according to the automation or P&ID diagrams. If the P&ID uses hierarchical naming, the first part (prefix) can occupy the UNIT position, and the second part (starting with the functional letter) can take the INSTRUMENT position. Instead of numeric P&ID loop identifiers, alternative loop symbols may be used. The framework does not regulate diagram identification rules, but it is recommended to use identifiers consistent with P&ID diagrams.
• SIGNAL: clarifying information about the signal, as the same automation means in a P&ID may have multiple inputs/outputs. It may be omitted if the device has only one signal connected to the PLC.

Examples:

T101_TT1          - temperature TT1 in tank T101
T101_TT1_PV       - temperature TT1 in tank T101 (alternative)
T101_LS1          - level switch
T101_LSH          - level switch (alternative)
T101_TV1_CPOS     - control output for valve TV1
T101_TV1_POS      - valve TV1 current position

If a process variable is reserved for future use, it is recommended to use the following naming templates:

REZDI1   - reserved DIVAR
REZDI22  - reserved DIVAR
REZAI1   - reserved AIVAR
REZDO1   - reserved DOVAR
REZAO1   - reserved AOVAR

Suffix Recommendations

All suffixes for output signals should begin with the letter C, while input signals should not begin with C.

DI (Digital Inputs)

• ALM: alarm status, e.g., T101_TY1_ALM - frequency converter alarm signal
• LSTP: “Local Stop” button pressed
• PWR: control circuit power available
• RDY: device ready
• RMT: local/remote switch status
• RUN: device operating
• SCLS: closed position
• SOPN: open position
• SPDC: discrete speed sensor contact (e.g., inductive)
• WRN: warning status
• WRK: device operating

AI (Analog Inputs)

• ECUR: motor current
• POS: actuator position
• PV: process variable (current value)
• SPD: actual speed/frequency

DO (Digital Outputs)

• CBWR: move backward (motion control)
• CCLS: command close
• CFRW: move forward (motion control)
• COPN: command open (or open/close)
• CRMT: enable/disable remote control
• CRVRS: reverse control or reverse/stop
• CSTRT: start control or start/stop
• CSTP: stop control
• CUP: increase command (can use COPN)
• CDN: decrease command (can use CCLS)
• CBLK: remote block command
• CCLR: alarm reset command

AO (Analog Outputs)

• CSPD: set speed/frequency
• CPOS: set actuator position

<– 1.4 General requirements for the implementation of the PACFramework interface

–> 1.6. The concept of classification and customization of objects

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