SCADA·Wiz

// field calculators · v0.1

Runs entirely in your browser. No login, no calls out, works on an air-gapped engineering laptop once the page is loaded.

local · offline-capable · nothing logged

SCALE Analog scaling

4–20mA, raw counts, and engineering units — one linear transform, any direction. NAMUR NE43 fault band flagged.

Engineering units50.000
Raw / mA12.000
Raw (hex)
Span position50.0 %
NE43 status— in range —

BASE Hex / dec / bin / octal

Live cross-conversion with word size and two's-complement view for reading register dumps.

Signed (two's comp)12
Bytes00 0C

DNP Point index ↔ word / shift

Flat point index to packed word and bit position. word = index ÷ N, shift = index mod N.

Word1
Shift1
Back to index33

Type an index, or fill word + shift to go the other way.

NET IPv4 subnet

CIDR or mask to network, broadcast, usable range and host count. Plus an in-subnet check.

Network192.168.1.0
Broadcast192.168.1.255
Usable range.1 – .254
Usable hosts254
Resultinside

MBUS Modbus register decoder

Two 16-bit registers → int / uint / float32, with word and byte order swaps. The endianness mess, solved.

Float32 (IEEE 754)50.240
Int32 (signed)1112343491
UInt321112343491
Reg1 int16 / uint1616968 / 16968
Assembled bytes42 48 F5 C3

Order = byte sequence after swap. ABCD = big-endian, reg1 high.

LOOP 4–20mA loop burden

Max load resistance the loop can drive, and whether a planned total burden stays in compliance at 20mA.

Max load @ 20mA600 Ω
Drop @ 20mA5.00 V
Headroom7.00 V
Statusin compliance

Max load = (supply − transmitter min) ÷ 0.020 A.

√DP DP flow scaler

Flow through a DP element goes as √(differential pressure). A linear scaler gives the wrong number — this doesn't.

Flow70.7 %
Flow (units)70.71
DP50.0 %

Half the DP signal is ~71% flow, not 50%. That's the trap.

DBND Deadband converter

How much the signal must change to register a change of state — shown in both raw and engineering units.

Must change by (raw)204.75
Must change by (EU)7.500
As % of span5.000 %

A setting of 5 with "% of span" means a 5% move; with "Raw value" it means 5 counts.