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SCADA — I/O point summary

Sample project — Tower A · detailed profile · 15 % spare

Generated 18 Oct 2026 18:00
Equipment schedule → point templates → I/O summary, field devices, soft-integration composition
Project code SAMPLE

Systems

Units

Hardwired I/O

With 15 % spare

Soft points

1,060

Field devices

Alarm points

1. Basis

Item	Value
System	SCADA
Template profile	detailed
Spare on hardwired points	15 % per type, rounded up per system
Protocols	BACnet/IP · BACnet MS/TP · Modbus RTU (RS-485)
Code regime	Indian — NBCS 2026 (SP 7:2026), which replaced NBC 2016 on 30 Apr 2026

2. System-wise summary (including spare)

Sr	System	Location	Qty	AI	DI	DO	SI	Hardwired	Total incl. spare
1	HT breaker (33 kV / 11 kV)	Substation · GF · HT room	4	0	12	0	80	12	94
2	Power / distribution transformer	Substation · GF · Transformer bay	2	4	12	0	0	16	19
3	LT main ACB / bus coupler / capacitor source	Substation · GF · LT room	6	0	24	12	120	36	162
4	DG set with synchronising panel	Substation · GF · DG room	2	6	6	0	60	12	74
5	Multi-function meter — LT panel feeder	Substation · GF · LT room	40	0	0	0	800	0	800
6	SCADA PLC panel health monitoring	Substation · GF · SCADA room	1	0	2	0	0	2	3
	TOTAL		55	10	56	12	1060	78	1151

3. I/O point summary

Sr	Description	Qty	AI	DI	DO	SI	Mon	Ctl	Alm	Remarks
ELECTRICAL
1	HT breaker (33 kV / 11 kV) Substation · GF · HT room	4				80
i	Breaker ON / OFF Status			4			●			Potential Free Contact to SCADA from HT / LT Panel
ii	Breaker Trip Status			4			●		●	Potential Free Contact to SCADA from HT / LT Panel
iii	Breaker Auto / Manual Status			4			●			Potential Free Contact to SCADA from HT / LT Panel
iv	Protocol integration (soft points)					80	●			Modbus/BACnet Integration — MFM at 20 registers per breaker
2	Power / distribution transformer Substation · GF · Transformer bay	2
i	Transformer HV / LV Breaker ON / OFF Status			2			●			A transformer has no ON/OFF of its own — this is its incomer and outgoing breaker status. Potential Free Contact to SCADA from HT / LT Panel
ii	Transformer Trip Status			2			●		●	Potential Free Contact to SCADA from HT / LT Panel
iii	Winding Temperature Alarm			2			●		●	Potential Free Contact to SCADA from HT / LT Panel
iv	Winding Temperature Trip			2			●		●	Potential Free Contact to SCADA from HT / LT Panel
v	Oil Temperature Alarm			2			●		●	Potential Free Contact to SCADA from HT / LT Panel
vi	Oil Temperature Trip			2			●		●	Potential Free Contact to SCADA from HT / LT Panel
vii	Winding Temperature Value		2				●			4-20 mA output from WTI. Previously only alarm and trip contacts — no trendable value.
viii	Oil Temperature Value		2				●			4-20 mA output from OTI. Previously only alarm and trip contacts — no trendable value.
3	LT main ACB / bus coupler / capacitor source Substation · GF · LT room	6				120
i	Breaker ON / OFF Command				12			●		Potential Free Contact from SCADA to LT Panel. 2 DO per breaker (close and open), subject to the local/remote selector being in Remote. Scope of remote switchin
ii	Breaker ON / OFF Status			6			●			Potential Free Contact to SCADA from HT / LT Panel
iii	Breaker Trip Status			6			●		●	Potential Free Contact to SCADA from HT / LT Panel
iv	Breaker Auto / Manual Status			6			●			Potential Free Contact to SCADA from HT / LT Panel
v	Breaker Spring Charged Status			6			●			Potential Free Contact to SCADA from HT / LT Panel
vi	Protocol integration (soft points)					120	●			Modbus/BACnet Integration — MFM at 20 registers per breaker
4	DG set with synchronising panel Substation · GF · DG room	2				60
i	DG Internal and Outer Fuel Tank Low Level			4			●		●	Sensor & field wiring — flame proof level switch
ii	DG Fuel Tank Continuous Level Measurement		4				●			Level switches alone give no available run time. 4-20 mA transmitter on day and bulk tanks.
iii	DG Battery Under Voltage Fault			2			●		●	Sensor & field wiring — DC voltage transducer
iv	DG Battery Voltage Value		2				●			The DC voltage transducer is already provided; its analogue output was discarded and only a threshold contact was taken.
v	Protocol integration (soft points)					60	●			Modbus/BACnet Integration — 30 parameters per set: start/stop, sync panel status, auto/manual, on-load/off-load, low oil pressure warning and shutdown, hot wate
ENERGY AND METERING
5	Multi-function meter — LT panel feeder Substation · GF · LT room	40				800
i	Protocol integration (soft points)					800	●			MOVED from the BMS I/O Summary and re-based at 20 registers per meter. The SCADA polls these meters once; the BMS reads a 5-parameter subset from the SCADA serv
SYSTEM HEALTH
6	SCADA PLC panel health monitoring Substation · GF · SCADA room	1
i	Panel Door Open Status			1			●		●
ii	Panel Auxiliary Supply Healthy Status			1			●		●	PLC auxiliary supply is from the substation UPS / DC system; loss of it stops event recording.

4. Field device schedule

Device	Quantity	Principal application
Transformer WTI/OTI with 4-20 mA Output	4	Power / distribution transformer (4)
Flame Proof Level Switch	4	DG set with synchronising panel (4)
Fuel Level Transmitter	4	DG set with synchronising panel (4)
DC Voltage Transducer	2	DG set with synchronising panel (2)

5. Soft-integrated points

Subsystem	Units	SI	Per unit	Nature
HT breaker (33 kV / 11 kV)	4	80	20	Modbus/BACnet Integration — MFM at 20 registers per breaker
LT main ACB / bus coupler / capacitor source	6	120	20	Modbus/BACnet Integration — MFM at 20 registers per breaker
DG set with synchronising panel	2	60	30	Modbus/BACnet Integration — 30 parameters per set: start/stop, sync panel status, auto/manual, on-load/off-load, low oil pressure warning and shutdown, hot wate
Multi-function meter — LT panel feeder	40	800	20	MOVED from the BMS I/O Summary and re-based at 20 registers per meter. The SCADA polls these meters once; the BMS reads a 5-parameter subset from the SCADA serv

6. Panels and system architecture

Panels

Controllers

I/O modules

Channels used

78 / 128

NLC / trunks

1 / 1

Cable (est.)

2,520 m

Panel	Location	Trunk	Ctrl	DI	DO	AI	Modules	Spare ch.	Equipment
RTU-GF-01	Substation · floor GF · DG room	NLC-01/T1	1	6	0	6	2	12	DG-01, DG-02
RTU-GF-02	Substation · floor GF · HT room	NLC-01/T1	1	12	0	0	1	4	HT-VCB-01, HT-VCB-02, HT-VCB-03, HT-VCB-04
RTU-GF-03	Substation · floor GF · LT room	NLC-01/T1	1	24	12	0	4	12	LT-ACB-01, LT-ACB-02, LT-ACB-03, LT-ACB-04, LT-ACB-05, LT-ACB-06
RTU-GF-04	Substation · floor GF · SCADA room	NLC-01/T1	1	2	0	0	1	14	SCADA-PLC
RTU-GF-05	Substation · floor GF · Transformer bay	NLC-01/T1	1	12	0	4	2	8	TR-01, TR-02

Bill of materials

Item	Qty	Note
BMS server (head-end) with software licence	2	hot standby
Operator workstation with 2 × 24" monitors	2
Core network switch (L3, managed)	1
Network-level controller (NLC / supervisory)	1	BACnet/IP backbone
RTU / PLC panel enclosure IP54	5
DDC controller	5	≤ 256 points each
DI module, 16 channels	6
DO module, 8 channels	2
AI module, 8 channels	2
Third-party integration (gateway / driver licence)	4	HT breaker (33 kV / 11 kV), LT main ACB / bus coupler / capacitor source, DG set with synchronising panel, Multi-function meter — LT panel feeder

7. Worked examples — from this project

Worked from this project’s own inputs and results — each value can be traced to the schedules above.

System 3 — LT main ACB / bus coupler / capacitor source (LT-ACB)

the system with the most hardwired points in this schedule

Given: Quantity 6 units · Substation · GF · LT room · Spare 15 % per point type, rounded up per system

1. DI points: DI = Σ per-unit × qty + Σ per-system = (1 + 1 + 1 + 1) × 6 = 24

2. DO points: DO = Σ per-unit × qty + Σ per-system = (2) × 6 = 12

3. Hardwired total: AI + DI + AO + DO = 0 + 24 + 0 + 12 = 36

4. DI with spare: DI + ⌈DI × 15 %⌉ = 24 + ⌈3.60⌉ = 24 + 4 = 28

5. DO with spare: DO + ⌈DO × 15 %⌉ = 12 + ⌈1.80⌉ = 12 + 2 = 14

6. Total incl. spare: Σ (type + spare) + SI = 0 + 28 + 0 + 14 + 120 SI = 162 (soft points carry no spare)

Project totals with spare

spare applied once on the project total per type (rounded up)

1. AI: AI + ⌈AI × 15 %⌉ = 10 + ⌈1.50⌉ = 12

2. DI: DI + ⌈DI × 15 %⌉ = 56 + ⌈8.40⌉ = 65

3. DO: DO + ⌈DO × 15 %⌉ = 12 + ⌈1.80⌉ = 14

4. Hardwired incl. spare: Σ = 12 + 65 + 14 = 91 (78 without spare)

Panel RTU-GF-03 — Substation · floor GF · LT room

the most loaded controller panel of the architecture

Given: Equipment LT-ACB-01, LT-ACB-02, LT-ACB-03, LT-ACB-04, LT-ACB-05, LT-ACB-06 · Controller 256 points, 1 per panel

1. Raw points per panel (room for spare): N_max = ⌊points/controller × controllers/panel / (1 + spare)⌋ = ⌊256 × 1 / 1.15⌋ = 222

2. Panel loading: N ≤ N_max → 36 ≤ 222 PASS

3. DI modules: ⌈DI × (1 + spare) / 16 ch⌉ = ⌈24 × 1.15 / 16⌉ = ⌈1.72⌉ = 2 (32 channels, 8 spare = 33 %)

4. DO modules: ⌈DO × (1 + spare) / 8 ch⌉ = ⌈12 × 1.15 / 8⌉ = ⌈1.72⌉ = 2 (16 channels, 4 spare = 33 %)

5. Controllers: ⌈Σ channels / points per controller⌉ = ⌈48 / 256⌉ = 1

6. Spare channels: spare ≥ 15 % per type → DI 8/24, DO 4/12 PASS

8. Codes and standards

Indian code edition: NBCS 2026 (SP 7:2026) — National Building Construction Standards (replaced NBC 2016 on 30 Apr 2026).

NBCS 2026 clause	PDF page	Governs
Part D Sec 2 cl. 4.2	1671–	Substation and switch rooms — HV, transformer and LV switchgear monitored by the SCADA
Part D Sec 2 cl. 4.2.1 (jj)	1674–1675	Fire and life-safety loads on normal + standby supply with changeover
Part D Sec 2 cl. 4.3–4.5	1680–1681	DG sets; battery storage with gas monitoring; multiple sources — synchronisation and priority
Part D Sec 2 cl. 4.8	1682	Substation safety
Part D Sec 2 cl. 10.4.2	1748	Integration of substation, renewable and standby generation with the BMS

Standard	Title	Used for
ISO 16484 (Parts 1–6)	Building automation and control systems	System design, hardware, functions, data communication (BACnet) for the BMS
ASHRAE Standard 135 / ISO 16484-5 (BACnet)	Data communication protocol for building automation and control networks	Backbone and controller network protocol
ASHRAE Guideline 36	High-performance sequences of operation for HVAC systems	Control narratives for AHUs, plants and zones
ASHRAE Guideline 13	Specifying building automation systems	Point classification, spare capacity, graphics and alarm philosophy
Modbus Application Protocol V1.1b3 / Serial Line V1.02	Modbus protocol specifications	Third-party integration of drives, meters, chillers, UPS and plant PLCs
IEC 61131-2 / -3	Programmable controllers — equipment requirements and programming languages	PLC panels for tunnel / car-park ventilation, lighting and electrical SCADA
IEC 61439-1/2:2020 / IS/IEC 61439	Low-voltage switchgear and controlgear assemblies	Panel construction (TTA/PTTA), busbar short-time withstand (Icw 1 s), temperature rise, IP rating
IEC 62443 (series)	Security for industrial automation and control systems	Zones and conduits, user management, hardening of the automation network
IEC 61850	Communication networks and systems for power utility automation	Substation SCADA — relays, IEDs, GOOSE / MMS
IEC 60870-5-104	Telecontrol equipment and systems — network access	Electrical SCADA telecontrol over TCP/IP
NBCS 2026 (SP 7:2026) Part D Sec 2	National Building Construction Standards — Electrical and allied installations	Load assessment and diversity, circuits, cables (4-core), earthing, lightning protection, standby supply for fire & life-safety loads
NBCS 2026 (SP 7:2026) Part D Sec 3	National Building Construction Standards — Air conditioning, heating and mechanical ventilation	Design conditions (Table 3), ventilation (Table 7), duct velocities (Table 18), clean rooms (Table 31), automation
NBCS 2026 (SP 7:2026) Part D Sec 5	National Building Construction Standards — Lifts, escalators, moving walks and power-driven parking	Lift traffic, fire-fighting lifts, controls
NBCS 2026 (SP 7:2026) Part D Sec 6	National Building Construction Standards — Information and communication enabled installations	Structured cabling, Wi-Fi (IEEE 802.11ax/be), ICT spaces
NBCS 2026 (SP 7:2026) Part F	National Building Construction Standards — Fire and life safety	Means of egress (Tables 2–4, cl. 4.4.2), staircase / lobby / lift-well pressurisation (cl. 4.4.2.5, Table 5), emergency lighting (cl. 3.5.6), fire-fighting installations by occupancy (Tables 7A–7J), demand, pumps and duration (Tables 7K / 7M), mains (Table 8), hydrant pressure 3.5–7 bar (cl. 5.1.1 f), sprinklers (cl. 5.1.3), gaseous suppression (cl. 5.1.6 / 5.1.9)
CEA (Measures relating to Safety and Electric Supply) Regulations, 2023	Central Electricity Authority safety regulations	Statutory safety requirements for installations
IS 732:2019	Code of practice for electrical wiring installations	Voltage-drop limits, cable selection, protection coordination (adopts IEC 60364)
IS 3043:2018	Code of practice for earthing	Earth bus, strip sizing, earthing of panels (future earthing tool)
CPWD General Specifications for Electrical Works Part VI (BMS)	Building management system specification	Panels, cabling, controllers and head end for CPWD works

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Results are design aids computed by designlink calc (calc.designlink.in) and must be reviewed by a qualified engineer before issue. Ground levels marked "assumed" have no survey level within reach — verify.