Schneider Sepam series 20 relay (needs ACE949/959 interface)

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.

structure-verified

Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.

point	address (0-based)	type	scale	unit
Binary time (year)	2	U16	1	year
Binary time (months + days)	3	U16	1
Binary time (hours + minutes)	4	U16	1
Binary time (milliseconds)	5	U16	1	ms
Manufacturer identification	6	U16	1
Equipment	7	U16	1
Marking + equipment type	8	U16	1
Modbus version	9	U16	1
Application version	10	U32BE	1
Sepam check-word	12	U16	1
Synthesis zone	13	U16	1
Command	14	U16	1
Extension address	15	U16	1
Exchange word	64	U16	1
Exchange word	112	U16	1
Sepam check-word	256	U16	1
TS1-TS16	257	U16	1
TS17-TS32	258	U16	1
TS33-TS48	259	U16	1
TS49-TS64	260	U16	1
Logic inputs	261	U16	1
I1 phase current (gain x 1) (S2x/T2x/M2x)	262	U16	0.1	A
I2 phase current (gain x 1) (S2x/T2x/M2x)	263	U16	0.1	A
I3 phase current (gain x 1) (S2x/T2x/M2x)	264	U16	0.1	A
I0 residual current (gain x 1) (S2x/T2x/M2x)	265	U16	0.1	A
Im1 average phase current (x 1) (S2x/T2x/M2x)	266	U16	0.1	A
Im2 average phase current (x 1) (S2x/T2x/M2x)	267	U16	0.1	A
Im3 average phase current (x 1) (S2x/T2x/M2x)	268	U16	0.1	A
I1 phase current (gain x 10) (S2x/T2x/M2x)	269	U16	1	A
I2 phase current (gain x 10) (S2x/T2x/M2x)	270	U16	1	A
I3 phase current (gain x 10) (S2x/T2x/M2x)	271	U16	1	A
I0 residual current (gain x 10) (S2x/T2x/M2x)	272	U16	1	A
IM1 average phase current (x10) (S2x/T2x/M2x)	273	U16	1	A
IM2 average phase current (x10) (S2x/T2x/M2x)	274	U16	1	A
IM3 average phase current (x10) (S2x/T2x/M2x)	275	U16	1	A
IM1 peak demand phase current (S2x/T2x/M2x)	276	U16	1	A
IM2 peak demand phase current (S2x/T2x/M2x)	277	U16	1	A
IM3 peak demand phase current (S2x/T2x/M2x)	278	U16	1	A
Itrip1 tripping current	280	U16	10	A
Itrip2 tripping current	281	U16	10	A
Itrip3 tripping current	282	U16	10	A
Itrip0 tripping current	283	U16	1	A
Cumulative breaking current	284	U16	1	(kA)2
Number of operations	285	U16	1
Operating time	286	U16	1	ms
Charging time	287	U16	1	sec
Running hours counter	289	U16	1	hr
Thermal capacity used	290	U16	1	%
Operating time before overload tripping	291	U16	1	min
Waiting time after overload tripping	292	U16	1	min
Unbalance ratio	293	U16	1	% Ib
Starting time / overload	294	U16	0.1	sec
Starting current overload	295	U16	1	A
Start inhibit time delay	296	U16	1	min
Number of starts allowed	297	U16	1
Temperature 1	298	I16	1	°C
Temperature 2	299	I16	1	°C
Temperature 3	300	I16	1	°C
Temperature 4	301	I16	1	°C
Temperature 5	302	I16	1	°C
Temperature 6	303	I16	1	°C
Temperature 7	304	I16	1	°C
Temperature 8	305	I16	1	°C
TC1-TC16	496	U16	1
STC1-STC16	497	U16	1
Control of analog output	498	I16	1
Time delay	500	U16	0.1	sec

link settings as documented (unverified): RTU; default 19200 8E1; unit ID 1; FC 01,02,03,04,05,06,07,08,11,15,16,43; Modbus RTU protocol supported via ACE949-2, ACE959, ACE969TP-2, or ACE969FO-2 interfaces.

bench facts as documented (unverified)

terminals	Screw-type terminal blocks (CCA620) or ring lug connectors (CCA622)
A/B polarity	A/B/A'/B'
termination	Jumper for RS 485 network line-end impedance matching with load resistor (Rc = 150 Ohm)
connector	RJ45 socket to connect the interface to the base unit with a CCA612 cord
isolation	Galvanic isolation between RS 232 and RS 485 interfaces: 1000 Vrms, 50 Hz, 1 min
shield/ground	Connection of the earthing terminal by tinned copper braid with cross-section >= 6 mm2 or cable >= 2.5 mm2
response timeout	15 ms
inter-frame delay	3 ms
broadcast	supported
protocol notes	Response time Tr is less than 15 ms, including a 3-character silence (~3 ms at 9600 bauds).
identification notes	Supports Modbus function 43 sub-function 14 for reading device identification (VendorName, ProductCode, MajorMinorRevision, VendorURL, ProductName, ModelName, UserAppName).
FC 43 device ID	supported
power	24 to 250 V DC or 110 to 240 V AC
environment	Operating temperature: -25°C to +70°C
certifications	CE, UL 508/UL 60950, cUL, AS/NZS 60950

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

Integrators frequently encounter RS-485 polarity confusion when wiring the ACE949-2 interface to third-party Modbus masters, as the L+ and L- terminal designations may require swapping depending on the master's polarity convention. [source]
confirmed: comms.baud_rates [4800, 9600, 19200, 38400] and default_baud 19200 — confirmed by Schneider Electric Modbus communication manual
confirmed: facts.identification.fc43_device_id — confirmed by Sepam Series 20 User's Manual describing Modbus function 43 sub-function 14 support
confirmed: register map addresses (e.g., sepam_check_word @ 256, ts1_to_ts16 @ 257) — confirmed by Sepam Series 20 Modbus register documentation mapping 0x0100 (256) and 0x0101 (257)

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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