Watlow Series F4 controller

Register map(s) for this device, with a note of how far each has been checked. Addresses are 0-based, as on the wire. Scale and byte order are confirmed only at the hardware-verified rung.

coherence-checked

Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.

point	address (0-based)	type	scale	unit
input_1_value	100	I16	0.1
input_2_value	104	I16	0.1
input_3_value	108	I16	0.1
set_point_1	300	I16	0.1	V
set_point_2	319	I16	0.1	V
power_output_1a	103	I16	1	%
power_output_1b	107	I16	1	%
power_output_2a	111	I16	1	%
power_output_2b	115	I16	1	%
alarm_1_status	102	U16	1
alarm_2_status	106	U16	1
input_1_error	101	U16	1
input_2_error	105	U16	1
input_3_error	109	U16	1
cjc1_temp	1500	I16	0.1
cjc2_temp	1531	I16	0.1
line_frequency	1515	U16	1

link settings as documented (unverified): RTU; default 19200 8N1; unit ID 1; Protocol or parity should be 8, n, 1.

⚠ WARNING: Install high- or low temperature-limit control protection in systems where an over temperature fault condition could present a fire hazard or other hazard. — Starkest reads only; we never write a control register.

bench facts as documented (unverified)

terminals	Touch-safe, removable terminal blocks, accepts 12- to 22-gauge wire
A/B polarity	T+/R+, T-/R-
termination	May need termination and pull-up and pull-down resistors (120 ohm)
isolation	Sensor input isolation from input to input to output to communication circuitry is 500V~ (ac)
shield/ground	Shield on EIA/TIA-232 connections
protocol notes	Two sets of Modbus registers contain profile information: edit mode and run mode.
model register	0
serial register	1
firmware register	3
power	100-240V~ (ac), -15%, +10%; 50/60Hz, ±5% or 24-28V~ (ac/dc), -15%, +10% (order option), 39VA maximum power consumption
environment	Operating: 32 to 130°F (0 to 55°C), 0 to 90% RH, non-condensing. Storage: -40 to 158°F (-40 to 70°C)
accuracy	Calibration accuracy and sensor conformity: ±0.1% of span ±1 LSD @ 77°F ±5°F (25°C ±3°C) ambient
certifications	UL®/C-UL 916-listed, File # E185611, CE to EN 61010, NEMA 4X and IP65, CE EMC to EN 50082-2, CE EMC to EN 55011
doc revision	0600-0032-0000 Rev E, October 2000

field reports — community-sourced, unverified (checked 2026-06-11)

The Watlow F4 uses a one-register offset for Modbus addressing. To read a value at register address 100, some master systems (such as Red Lion G3 HMIs using Crimson 3.0) must be configured to read address 101. [source]
Modbus registers in the 4000 range (typically 4001-4999) used for storing ramp/soak profile data are write-only and cannot be read back via Modbus. [source]
The DB-9 connector on TestEquity chambers equipped with the Watlow F4 is wired to accommodate a null-modem cable (pins 2 and 3 swapped), meaning a standard straight-through RS-232 cable cannot be used. [source]
confirmed: comms: baud_rates [9600, 19200], default_baud 19200, default_unit_id 1, framing [RTU], parity N, stop_bits 1 — confirmed by Watlow Series F4 User's Manual and TestEquity integration guides
confirmed: facts: accuracy ±0.1% of span — confirmed by Watlow Series F4 ramping controller datasheet
confirmed: facts: certifications UL®/C-UL 916-listed, File # E185611, CE to EN 61010, NEMA 4X and IP65 — confirmed by Watlow Series F4 ramping controller datasheet
confirmed: facts: environment Operating: 32 to 130°F (0 to 55°C), 0 to 90% RH — confirmed by Watlow Series F4 ramping controller datasheet
confirmed: facts: identification firmware_register 3, model_register 0, serial_register 1 — confirmed by TestEquity AB48-25d Modbus Temp Ctlr manual
confirmed: facts: physical isolation 500VAC — confirmed by Watlow Series F4 ramping controller datasheet
confirmed: facts: physical polarity T+/R+, T-/R- — confirmed by Watlow Series F4 User's Manual and wiring diagrams
confirmed: facts: physical terminals accepts 12- to 22-gauge wire — confirmed by Watlow Series F4 ramping controller datasheet

The trust ladder

Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.

generated — A prompt produced it. Unproven — anyone can regenerate this.
structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
coherence-checked — Round-trips through a real Modbus stack with no overlapping addresses and a word-order-sensitive codec — the map is internally coherent and wire-decodable. Does NOT prove byte-order or scaling match a real device: the emulator is seeded from the map's own types, so a uniformly wrong byte-order still round-trips. Only hardware-verified confirms byte-order/scale on the wire.
hardware-verified (software-key) x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.

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