verified connector library

Keller Series 30X/33X/35X pressure transmitter

Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based as on the wire; word order and scaling are only confirmed at the hardware-verified rung.

interop-verified

Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.

pointaddress (0-based)typescaleunit
ch0_float0F32BE1
p1_float2F32BE1bar
p2_float4F32BE1bar
t_float6F32BE1°C
tob1_float8F32BE1°C
tob2_float10F32BE1°C
ch0_int1616I160.011/100
p1_int1617I160.011/100 bar
p2_int1618I160.011/100 bar
t_int1619I160.011/100 °C
tob1_int1620I160.011/100 °C
tob2_int1621I160.011/100 °C
ch0_int3232U32BE0.0000110-5
p1_int3234U32BE0.00001Pa
p2_int3236U32BE0.00001Pa
t_int3238U32BE0.011/100 °C
tob1_int3240U32BE0.011/100 °C
tob2_int3242U32BE0.011/100 °C
p1_alt_float256F32BE1bar
tob1_alt_float258F32BE1°C
p2_alt_float260F32BE1bar
tob2_alt_float262F32BE1°C
p1_alt2_float264F32BE1bar
t_alt_float266F32BE1°C
conductivity_temp_compensated268F32BE1mS/cm
min_pressure_p1928F32BE1bar
max_pressure_p1930F32BE1bar
min_pressure_p2932F32BE1bar
max_pressure_p2934F32BE1bar
min_temp936F32BE1°C
max_temp938F32BE1°C
min_temp_p1940F32BE1°C
max_temp_p1942F32BE1°C
min_temp_p2944F32BE1°C
max_temp_p2946F32BE1°C
min_ch0948F32BE1
max_ch0950F32BE1

link settings as documented (unverified): RTU; default 9600 8N1; FC 03,06,08,16; Both Modbus and Keller-Protocol are active. Modbus uses L:H CRC alignment, while Keller-Protocol uses H:L.

bench facts as documented (unverified)
terminalsRS485A, RS485B, GND and +Vcc
A/B polarityinverted (-) B / A (EIA Standard), non-inverted (+) A / B (EIA Standard)
termination120Ohm. The transmitters will never have a terminal resistor built in internally.
shield/groundAlways connect the GND of the RS485 converter of the master with GND of the transmitter!
wiring notesMax network length 1300m, max 128 devices. Each riser cable up to 14m.
max registers/read80
response timeout100 ms
inter-frame delay2 ms
broadcastsupported
sentinel valuesNaN (float) or ovl (integer) in case of an inactive channel or an error in the channel. 32767 for 16bit overflow/error, -32768 for underflow. 2147483647 for 32bit overflow/error, -2147483648 for underflow.
protocol notesA silent interval of more than 1.5 character times between characters declares the message frame incomplete.
model register0x020E
serial register0x0202
firmware register0x020E
FC 43 device IDnot supported
power2 wires for power in feed
doc revisionVersion 3.4 BV/SM 14. Oktober 2015
firmware applicabilityClass.Group = 5.20, Class.Group = 5.21

generated by gemini:gemini-3.5-flash · harvested from https://www.instrumart.com/assets/Keller-CommunicationProtocol.pdf (Keller); manual-faithful — the document's claims, panel risk: ELEVATED — panel is not confident; proved interop-verified on 2026-06-10 · recorded 2026-06-10

The trust ladder

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

Have a device that isn't here? Upload its register map — generation is free, and the connector earns its rung by being proven, not claimed.

Need it proven on your own device? Hardware verification — if it doesn't verify, you don't pay.

Building a platform? License the verified library — machine-readable maps, firmware matrix, API access.