I/O List

Tag,Description,Signal Type,I/O Type,Rack,Slot,Channel,Address,Panel,Terminal,Cable,Core,Field Device,Manufacturer,Model,Range Low,Range High,Units,Fail Safe State,Normally,Alarm Low,Alarm High,Trip,Interlock Ref,Loop Drawing,Tested FAT,Tested SAT,Comment
XV-101-ZSO,Inlet valve open limit,24VDC Sourcing,DI,1,2,0,%I0.0,CP-01,X1:01,C-101,1,Proximity switch,,,,,,,NO,,,,INT-001,LD-101,,,
XV-101-ZSC,Inlet valve closed limit,24VDC Sourcing,DI,1,2,1,%I0.1,CP-01,X1:02,C-101,2,Proximity switch,,,,,,,NC,,,,INT-001,LD-101,,,
PB-START,Start pushbutton,24VDC Sourcing,DI,1,2,2,%I0.2,CP-01,X1:03,C-102,1,Pushbutton green,,,,,,,NO,,,,,LD-102,,,
PB-STOP,Stop pushbutton,24VDC Sourcing,DI,1,2,3,%I0.3,CP-01,X1:04,C-102,2,Pushbutton red,,,,,,,Energised,NC,,,,,LD-102,,,
ESTOP-01,Emergency stop station 1,24VDC Dual channel,DI Safety,1,3,0,%I2.0,CP-01,X2:01,C-103,1-2,E-stop mushroom,,,,,,,De-energised,NC,,,Yes,SF-001,LD-103,,,
GS-101,Guard door switch,24VDC Dual channel,DI Safety,1,3,2,%I2.2,CP-01,X2:03,C-104,1-2,Interlock switch,,,,,,,De-energised,NC,,,Yes,SF-002,LD-104,,,
FT-101,Feed flow transmitter,4-20mA 2-wire,AI,1,4,0,%IW64,CP-01,X3:01,C-201,1-2,Flow transmitter,,,0,50,m3/h,Hold last,,5,45,,,LD-201,,,
LT-101,Feed tank level,4-20mA 2-wire,AI,1,4,1,%IW66,CP-01,X3:03,C-202,1-2,Level transmitter,,,0,100,%,Hold last,,10,90,95,INT-002,LD-202,,,
TT-101,Reactor temperature,RTD Pt100 3-wire,AI,1,5,0,%IW80,CP-01,X4:01,C-203,1-3,RTD,,,0,200,degC,Upscale,,,150,180,INT-003,LD-203,,,
MTR-101-RUN,Feed pump run command,24VDC Sourcing,DO,1,6,0,%Q0.0,CP-01,X5:01,C-301,1,Contactor coil,,,,,,,De-energised,,,,,,LD-301,,,
MTR-101-FBK,Feed pump running feedback,24VDC Sourcing,DI,1,2,4,%I0.4,CP-01,X1:05,C-301,2,Auxiliary contact,,,,,,,NO,,,,,LD-301,,,
XV-101-SOL,Inlet valve solenoid,24VDC Sourcing,DO,1,6,1,%Q0.1,CP-01,X5:02,C-302,1,Solenoid valve,,,,,,,De-energised,,,,,,LD-302,,,
LMP-FAULT,Fault beacon,24VDC Sourcing,DO,1,6,2,%Q0.2,CP-01,X5:03,C-303,1,Beacon red,,,,,,,De-energised,,,,,,LD-303,,,
FCV-101,Feed control valve,4-20mA,AO,1,7,0,%QW96,CP-01,X6:01,C-401,1-2,Control valve positioner,,,0,100,%,Fail closed,,,,,,LD-401,,,

# I/O List, conventions and column guide
## {{PROJECT_NAME}}

| | |
|---|---|
| **Document title** | I/O List, conventions and column guide (I/O) |
| **Document number** | {{DOC_NO}} |
| **Revision** | {{REV}} |
| **Date** | {{DATE}} |
| **Project** | {{PROJECT_NAME}} |
| **Client** | {{CLIENT}} |
| **Prepared by** | {{AUTHOR}}, {{COMPANY}} |

### Revision history

| Rev | Date | Description | Author | Approved |
|---|---|---|---|---|
| 0 | {{DATE}} | First issue | {{AUTHOR}} | |
| | | | | |

### Approval

| Role | Name | Signature | Date |
|---|---|---|---|
| Author | {{AUTHOR}} | | |
| Reviewer (engineering) | | | |
| Approver ({{COMPANY}}) | | | |
| Approver ({{CLIENT}}) | | | |

---

## How to use this list

The CSV is the deliverable. This note explains the columns and the conventions, so that the
list stays consistent when several people edit it.

## Column guide

| Column | What goes in it | Why it matters |
|---|---|---|
| Tag | Unique identifier, per ISA-5.1 | The primary key. Never reuse a tag, even after a device is removed. |
| Description | Plain language, 40 characters or fewer | This becomes the HMI text and the alarm text. Write it for an operator at 3 am. |
| Signal Type | Electrical nature, e.g. 24VDC Sourcing, 4-20mA 2-wire, RTD Pt100 3-wire | Decides the card, and decides whether a barrier is needed. |
| I/O Type | DI, DO, AI, AO, and the Safety variants | Drives the card count. |
| Rack / Slot / Channel | Physical location | The path from a tag to a screw terminal. |
| Address | Controller address | Vendor specific. Keep the vendor's own syntax. |
| Panel / Terminal | Where it lands in the panel | The panel builder works from this. |
| Cable / Core | Field cable and core number | Must agree with the cable schedule. |
| Range Low / High / Units | Engineering range for analog | Must agree with the transmitter configuration, not with what somebody hoped. |
| Fail Safe State | What the signal does on failure | The column most often left blank and most often needed. |
| Normally | NO or NC for discrete field devices | Determines whether a broken wire reads as safe or as normal. |
| Alarm Low / High / Trip | Limits | Feeds the RATS and the alarm list. |
| Interlock Ref | Cross reference to the FDS | Ties this signal to the logic that uses it. |
| Loop Drawing | Drawing number | Where to look when it does not work. |
| Tested FAT / SAT | Sign-off | Initial and date. This is the evidence. |

## Conventions worth holding to

**Fail safe direction.** Stop circuits and safety devices are normally closed, so that a broken
wire or a lost supply produces the safe state. If a column says NO for an E-stop, that is a
finding, not a preference.

**Spare capacity.** Carry at least 20 percent spare channels of each type at handover, and list
the spares explicitly with a Spare tag rather than leaving gaps. Gaps get filled by accident.

**Analog fail state.** "Hold last" is a decision, not a default. A held value on a failed flow
transmitter will keep a sequence running that should have stopped. Decide per signal.

**Do not renumber.** Once the panel is wired, a tag change is a change to the panel, the
drawings, the program and the HMI. Add, do not renumber.