Modbus Register Table

Complete register mapping for the iCartridge 2.0 Modbus RTU interface.

Slave ID: 0x66 (102 decimal)  |  Baud Rate: 115200  |  Config: 8N1

Input Registers (Read-Only)

Reference 3xxxx - Function 0x04 Read Input Register

Register	Description	Data Type	Unit
30001	Temperature	int16_t	deci °C
30002	Process Pressure	int16_t	centibar
30003	Barrier Fluid Pressure	int16_t	centibar
30004	Delta Pressure (Process - Barrier Fluid)	int16_t	centibar
30005	Pump Power	int16_t	centiwatts
30006	Current Year	int16_t	e.g. 2025
30007	Current Month	int16_t	1-12
30008	Current Day	int16_t	1-31
30009	Current Hour	int16_t	0-23
30010	Current Minute	int16_t	0-59
30011	Current Second	int16_t	0-59
30012	External Accelerometer X-axis	int16_t	mg
30013	External Accelerometer Y-axis	int16_t	mg
30014	External Accelerometer Z-axis	int16_t	mg
30015	Onboard Accelerometer X-axis	int16_t	mg
30016	Onboard Accelerometer Y-axis	int16_t	mg
30017	Onboard Accelerometer Z-axis	int16_t	mg

Holding Registers (Read/Write)

Reference 4xxxx - Function 0x03 Read / 0x06 Write Holding Register

Register	Description	Data Type	Unit / Notes
40001	Temperature Setpoint	int16_t	deci °C
40002	Pressure Difference (dP) Setpoint	int16_t	centibar
40003	PID P parameter (temperature)	int16_t	×100, typical 100-2000 (1.0-20.0)
40004	PID I parameter (temperature)	int16_t	×1000/sec, typical 0-2000 (0.0-2.0)
40005	PID D parameter (temperature)	int16_t	×1000 sec, typical 0-1000 (0.0-1.0)
40006	PID Output (temperature)	int16_t	deci %
40007	Deadband (dP)	int16_t	centibar, typical 10-50 (0.1-0.5 bar)
40008	Minimum Pulse Time (dP)	int16_t	centiseconds
40009	Set Year	int16_t	e.g. 2025, -1 to skip
40010	Set Month	int16_t	1-12, -1 to skip
40011	Set Day	int16_t	1-31, -1 to skip
40012	Set Hour	int16_t	0-23, -1 to skip
40013	Set Minute	int16_t	0-59, -1 to skip
40014	Set Second	int16_t	0-59, -1 to skip
40015	Pressure Hysteresis (dP)	int16_t	centibar, typical 10-50 (0.1-0.5 bar)

Coils (Read/Write)

Reference 0xxxx - Function 0x01 Read / 0x05 Write Single Coil

Address	Description	Type
00001	Auto/Manual PID control for temperature (1=Auto, 0=Manual)	bool
00002	Auto/Manual ON/OFF control for dP (1=Auto, 0=Manual)	bool
00003	Output solenoid valve 1 (pressure increase)	bool
00004	Output solenoid valve 2 (pressure decrease)	bool

Discrete Inputs (Read-Only)

Reference 1xxxx - Function 0x02 Read Discrete Inputs

Address	Description	Type
10001	Status iCartridge 2.0 - Error	bool
10002	Status iCartridge 2.0 - State	bool
10003	Process Pressure sensor ready	bool
10004	Barrier Fluid Pressure sensor ready	bool
10005	Pump feedback ready	bool
10006	Temperature sensor ready	bool
10007	Pump Standby (true = standby/stop)	bool
10008	Pump Fault - Blocked (true = alarm, blocked pump)	bool
10009	Pump Fault - Electrical (true = alarm, electrical fault)	bool
10010	Pump Warning (true = warning condition)	bool
10011	External Accelerometer ready	bool
10012	Onboard Accelerometer ready	bool

Unit Conversion Reference

Stored Unit	Conversion	Example
deci °C	× 0.1 = °C	250 → 25.0 °C
centibar	× 0.01 = bar	150 → 1.50 bar
centiwatts	× 0.01 = W	500 → 5.00 W
centiseconds	× 0.01 = s	100 → 1.00 s
mg	× 0.001 = g	1000 → 1.000 g

PID Parameters

PID sample time is 1 second.

Parameter	Conversion	Example
Kp	register value / 100	150 → Kp = 1.50
Ki	register value / 1000	800 → Ki = 0.800 /s
Kd	register value / 1000	200 → Kd = 0.200 s

Default PID values: P=300 (Kp=3.0), I=0, D=0

Setting the RTC

Write valid values to registers 40009-40014 to update the real-time clock. After a successful update, all fields are automatically reset to -1.

Example - Set time to 2025-03-15 14:30:45:

Register	Value
40009 (Year)	2025
40010 (Month)	3
40011 (Day)	15
40012 (Hour)	14
40013 (Minute)	30
40014 (Second)	45

INFO

All six time fields must contain valid (positive) values for the RTC update to trigger. Fields are reset to -1 after a successful update to prevent repeated writes.