Appendix: Communication Interface Parameters

Board Level Data Objects

The data objects for the board itself. These objects are to be interpreted at the CPIM1000 level.

Index. SubIndex	Description	Payload	Object Type	Data Type	Access	Signed
1009.00	Hardware Version	Visible String payload consisting the HWVersion	VAR	Visible String	R	N
100a.00	Software Version SHA	32-byte SHA representing the software version of the CPIM1000	ARR[32]	UINT8	R	N
100a.01	Boot version SHA	32-byte SHA representing the boot version of the CPIM1000	ARR[32]	UINT8	R	N
100a.02	Safety Version SHA	32-byte SHA containing the safety version of the CPIM1000	ARR[32]	UINT8	R	N
100a.03	MID Measuring Instruments Directive LRS Version SHA	32-byte SHA containing the mid approved lrs version of the CPIM1000	ARR[32]	UINT8	R	N
100a.80	Device Identity	See Device Identity	ARR[288]	UINT8	R	Y
40.01	Board Status	See Board Status	VAR	UINT32	R	N
40.02	Holster Light	An unsigned 8-bit value controlling the holster light brightness. Off is represented by 0x00	VAR	UINT8	W	N
40.03	Board Self Test	See Board	VAR	UINT32	R	N
40.04	AC Board Temperature	See AC Board Temperature Register	VAR	UINT32	R	N
40.05	Power Plate Temperature	See Power Plate Temperature Register	VAR	UINT32	R	N
40.0A	Reset Cause	32 bit register Contains a copy of the STM32G473 RCC_CSR Register	VAR	UINT32	R	N
40.0B	Board Voltages 1	32 bit register Bit 0 to 15: Power Supply Voltage Bit 16-31: Holster Motor Voltage	VAR	UINT32	R	N
N40.0C	Board Voltages 2	32 bit register Bit 0 to 15: MCU Voltage Bit 16-31: Diff Coil Voltage	VAR	UINT32	R	N
40.0D	Device ID (DBGMCU _IDCODE) 1	32 bit register Contains the STM32G4 DBGMCU_IDCODE code	VAR	UINT32	R	N
40.0E	Diagnostic Register		VAR	UINT32	W	N
40.OF	Manufacturing Info	This is a 448-byte chunk of flash reserved for manufacturing information	VAR	Visible String	R	N
40.10	Calibration Data	The calibration data stored in flash memory	ARR[144]	UINT8	R	N
40.11	Meter Log Rate	An 8-bit integer that controls the sample rate for the meter log buffer	VAR	UINT8	W	N
40.13	Thread Flags	See Thread Flags Register	VAR	UINT8	R	N

Device Identity

288 byte payload consisting of the following:

CPIM1000 Public Key: 64-byte public key of the CPIM1000
Payload Signature: 64-byte signature of the Device Identity
UDID: 16-byte unique device identifier of the CPIM1000
Reserved: 112 bytes reserved, filled with 0’s
Boot Version: 32-byte SHA representing the boot version of the CPIM1000
App Version: 32-byte SHA representing the software version of the CPIM1000
Safety Version: 32-byte SHA containing the safety version of the CPIM1000
LRS Version: 32-byte SHA containing the MID Measuring Instruments Directive approved LRS Hash of the CPIM1000

Board Status

16-bit register as explained in the table below:

Bit	Name	Meaning	AC Board Response	System Response
0	BOOT	Indicates that the board is booting. This bit clears when the board becomes operational	This is normally transitory. Will not charge when set	Information only
1	INIT Err	Indicates that an error occurred during initialization	Will not charge	System should read the initialization error register for diagnostics and reboot
2	INIT	Indicates that the firmware is initializing	This is normally transitory. Will not charge when set	Information only
3	STKOVR	The stack has overflowed	Will not charge	Reboot required
4	CLK Err	Indicates a Clock error	Will not charge	Reboot required
5	RAM Err	Indicates a RAM error	Will not charge	Reboot required
6	FLSH Err	Indicates a Flash error	Will not charge	Reboot required
7	RESERVED
9:8	PPlate Type	01 = North America 10 = Europe All other values illegal	N/A	Verify
10	WDMA	Weld DMA test time out	Will not charge	Reboot required
11	CPU Err	Periodic cpu test failed	Will not charge	Reboot required
12	ADC Analog-Digital Converter Err	Indicates an ADC Analog-Digital Converter error	Will not charge
13	THREAD	Safety-critical thread time out	Will not charge	Log Thread Register; reboot required
14	GFERR	DiffCoil initialization	Will not charge	Log Thread; May recover
15	RESERVED

¹ See STM32G4 family reference manual, RM0440, 46.6.1 MCU device ID code

Board Self-Test

An unsigned 8-bit value, indicating which initialization step failed. If the board detects a malfunction during initialization, it will not become operational. This value contains a code that indicates the specific malfunction. This is diagnostic information.

AC Board Temperature Register

32-bit register as explained below:

Bit	Name	Function	Details
31:24	RESERVED	N/A	N/A
23:16	LTMP	Left AC Path Temp	See note
15:8	RTMP	Right AC Path Temp	See note
7:0	MTMP	STM32G temp	See note

Note: values are signed 8-bit numbers representing the temperature in °C. Values are clamped to 127 C°.

Power Plate Temperature Register

32-bit register as explained below:

Bit	Name	Function	Details
31:24	RESERVED	N/A	N/A
23:16	Temp 1	Power Plate 3 temperature	See note
15:8	Temp 2	Power Plate 2 temperature	See note
7:0	Temp 3	Power Plate 1 temperature	See note

Note: values are signed 8-bit numbers representing the temperature in °C. Values are clamped to 127 C

Thread Flags Register

8-bit register. Gives information on whether independent threads associated with a safety-critical determination are running as expected

Bit Number	Function
0	Reserved
1	If set, Indicates that the meter process has not completed in 1 second
2	If set, Indicates that the pilot process has not completed in 1 second
3	If set, Indicates that the diff coil process has not completed in 1 second
4	If set, Indicates that the self-tests have not completed in 60 seconds
5	Reserved
6	Reserved
7	Reserved

Port Level Objects

This section lists the object for the individual ports.

Index. SubIndex	Description	Payload	Object Type	Data Type	Access	Signed
41.01 41.81	PortStatus	See Port Status	VAR	UINT32	R	N
41.03 41.83	Charge Control	32-bit register Bit 0: CHA (Charging Control). 0 means charging disabled, 1 means charging enabled. CHA will reset automatically when Pilot status = (State A \| State E \| State F) Bit 1 to 31L UNUSED	VAR	UINT32	W	N
41.04 41.84	SEVC Smart Electric Vehicle Cable Power	8-bit register Bit 0: ENSC (Enable Smart Cable). 0 means smart cable power off, 1 means smart cable power on Bit 1 to 7: UNUSED	VAR	UINT8	RW	N
41.05 41.85	Holster Motor	8-bit register Bit 0: HLSTP (Holster Motor Control). 0 means move motor pin out, 1 means move motor pin in Bit 1 to 7: UNUSED	VAR	UINT8	RW	N
41.06 41.86	Coil Voltage	A floating-point number representing the relay coil voltage. This number is significant only when the REN bit in the Port Status register is set (indicating the relay coil is energized).	VAR	FLOAT	R	N
41.07 41.80	Holster Sense	32-bit register Bit 0 to 11: 12-bit value proportional to the voltage of the motor sense pin. To convert the value to volts, divide by 1241 Bit 12 to 31: UNUSED	VAR	UINT32	R	N
42.01 42.81	Signed Meter Blob	See Signed Meter Blob	ARR	UINT32	R	Y
42.02 42.82	Unsigned Meter Blob	See Unsigned Meter Blob	ARR	UINT32	R	N
43.01 43.81	Negative Energy Accumulat or	Reports the energy transmitted to EVs during the lifetime of the meter. Reported as watt-Hr, formatted as IEEE single precision floating point	VAR	FLOAT	R	N
43.02 43.82	Positive Energy Accumulat or	Reports the energy transmitted from EVs during the lifetime of the meter. Reported as watt-Hr, formatted as IEEE single precision floating point	VAR	FLOAT	R	N
43.03 43.83	Negative SumISqua red	Reports the Sum (Integral) of I2 for negative currents. Reports in A2- hours or W / Ohm. Returns as IEEE single precision floating point	VAR	FLOAT	R	N
43.04 43.84	Positive SumISqua red	Reports the Sum (Integral) of I2 for positive currents. Reports in A2- hours or W / Ohm. Returns as IEEE single precision floating point	VAR	FLOAT	R	N
44.00 44.80	Line 1 Voltage (Line A – Line D)	Line to Line Voltage for Line 1 in volts	VAR	FLOAT	R	N
44.01 44.81	Line 2 Voltage (Line B – Line D)	Line to Line Voltage for Line 2 in in volts	VAR	FLOAT	R	N
44.02 44.82	Line 3 Voltage (Line C – Line D)	Line to Line Voltage for Line 3 in volts	VAR	FLOAT	R	N
45.00 45.80	Va	Raw Line A Voltage in volts	VAR	FLOAT	R	N
45.01 45.81	Vb	Raw Line B Voltage in volts	VAR	FLOAT	R	N
45.02 45.82	Vc	Raw Line C Voltage in volts v	VAR	FLOAT	R	N
45.03 45.83	Vd	Raw Line D Voltage in volts	VAR	FLOAT	R	N
47.00 47.80	Line A current	Line A current in amps	VAR	FLOAT	R	N
47.01 47.81	Line B current	Line B current in volts	VAR	FLOAT	R	N
47.02 47.82	Line C current	Line C current in volts	VAR	FLOAT	R	N
47.03 47.83	Line D current	Line D current in volts	VAR	FLOAT	R	N
47.04 47.84	Current (Single Phase)	Single Phase Current in amps	VAR	FLOAT	R	N
48.00 48.80	Line A Power Factor	Line A Power Factor	VAR	FLOAT	R	N
48.01 48.81	Line B Power Factor	Line B Power Factor	VAR	FLOAT	R	N
48.02 48.83	Line C Power Factor	Line C Power Factor	VAR	FLOAT	R	N
48.03 48.83	Line D Power Factor	Line D Power Factor	VAR	FLOAT	R	N
49.00 49.80	Apparent Power	Apparent Power in watts
49.01 49.81	L1 Apparent Power	L1 Apparent Power in watts
49.02 49.82	L2 Apparent Power	L2 Apparent Power in watts
49.03 49.83	L3 Apparent Power	L3 Apparent Power in watts
4a.01 4a.81	Frequency	In Hz	VAR	FLOAT	R	N
4b.01 4b.81	Weld Voltage	An internal voltage in volts	VAR	FLOAT	R	N
4b.02 4b.82	Pilot Voltage	See Safe Pilot Voltage	VAR	FLOAT	R	N
4b.03 4b.83	Ground resistance	An internal resistance measurement in ohms	VAR	FLOAT	R	N
4b.04 4b.84	GM Test ADC Analog-Digital Converter		VAR	FLOAT	R	N
4b.05 4b.85	GM ADC Analog-Digital Converter		VAR	FLOAT	R	N
4c.00 4c.80	Meter sample Buffer – VA	Meter Sample buffer Va See Sample Buffers	ARR	INT16	R	N
4c.00 4c.80	Meter sample Buffer – IA	Meter Sample buffer for Ia See Sample Buffers	ARR	INT16	R	N
4c.01 4c.81	Meter sample Buffer – VB	Meter Sample buffer for Vb See Sample Buffers	ARR	INT16	R	N
4c.02 4c.82	Meter sample Buffer – IB	Meter Sample buffer for Ib See Sample Buffers	ARR	INT16	R	N
4c.03 4c.83	Meter sample Buffer – VC	Meter Sample buffer for Vc See Sample Buffers	ARR	INT16	R	N
4c.04 4c.84	Meter sample Buffer – IC	Meter Sample buffer for Ic See Sample Buffers	ARR	INT16	R	N
4c.05 4c.85	Meter sample Buffer – VD	Meter Sample buffer for Vd See Sample Buffers	ARR	INT16	R	N
4c.06 4c.86	Meter sample Buffer – origin	Meter Sample buffer for Id See Sample Buffers	ARR	INT16	R	N

Port Status

32-bit register as explained below.

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
								CHA	SHTRIP	LOGS		GMERR	RLYP	Weld
R	R	R	R	R	R	R	R	RC	RC	RC	RC	RC	RC	RC	RC

15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
		COVR	RSC	RSO	GMF	GFERR	GF	IGF	DCGF	HPOS	HWERR	REN	SAFEP
RC	RC	RC	RC	RC	RC	RC	RC	RC	R	R	R	R	R	R	R

Bits indicated “R” are read-only and not sticky. They represent the condition when read. Bits indicated “RC” are sticky. They will stay clear only when the condition has cleared, and the bit has been cleared by writing a “1” to the register. Unless specifically noted conditions clear when the detected condition resolves. For example, GMF clears when the unit is grounded.

Bit	Name	Meaning	Status register operation	AC Board Response	System Response
2:0	SAFEP	Safety pilot state	see Error! Reference source not found.	Relay will close and remain closed only when SAFEP is safe to charge; Relay will open within 100 ms if pilot is in state A and within 2 seconds when SAFEP is not in safe to charge	System should check that status reported by AC board matches status reported by SEVB Smart Ethernet Vehicle Board
3	REN	Relay coil energized	“1” - the relay coil is energized (contacts are closed or closing) “0” - the relay coil is de- energized		Information only
4	RESERVED
5	RESERVED
6	DCGF	DC ground fault (EU only)	Sets when fault occurs.	See SHTRIP Meter logging stops	Read Meter log, Write clear DCGF
7	IGF	Non-retriable ground fault (N.A. only)	Sets when ground fault occurs. Fault clears when EV Electric Vehicle disconnects (SAFEP = State A)	Relay opens Evident ind. Lights Meter logging stops	Turn off pilot OSC. Read meter log,
8	GF	Ground Fault (N.A. only) NA: AC ground fault EU: DC ground fault	Sets when ground fault occurs. Fault clears when EV Electric Vehicle disconnects (SAFEP = State A) or after 15 seconds.	Relay opens Evident ind. Blinks. After 15 seconds AND system has done write- clear, relay will close again. Meter logging stops	Must turn off pilot OSC. Read meter log. After 15 seconds, system may restart charging.
9	GFERR	DiffCoil initialization	Sets when error is detected.	NA: opens the relays. EU: see SHTRIP.	If persistent, maintenance is required
10	GMF	Grounding monitor fault	Sets when ground input impedance is high	Relay opens Evident ind. Lights Meter logging stops	Turn off pilot OSC; when fault clears system should retry
11	RSO	Relay stuck open	Sets when a relay contact that should be closed is open.		System should retry. How many retries, etc., is TBD
12	RSC	relay struck closed	Sets when a relay contact that should be open is closed	NA: Clamp pilot Evident indicator on EU: see SHTRIP	NA: System should put pilot into state F.
13	COVR	Contact over-current	Sets when the current on any path (A, B, C, or D) exceeds 50 A for 10 seconds or more.	Relay opens	System can retry at reduced power. If persistent reduce “pilot” PWM duty cycle (or 15118 equivalent).
14- 16	RESERVED
17	WELD	Weld detection circuit not operating (minimum voltage not reached)	Sets when the weld detect circuit is not operating or the input voltage is zero.	Stop charging Evident indicator on	System should put pilot into state F
18	RLYP	Incorrect Relay Coil GPIO General Purpose Input Output state	Sets when a GPIO General Purpose Input Output pin is in a unexpected state
19	GMERR	Grounding monitor circuit malfunction: GPIO General Purpose Input Output pins wrong or sense signal wrong	Sets when the grounding monitor circuit is not operating (NA only)	NA: Stop charging Evident Indicator on EU: not applicable	System should turn off oscillator. May retry if condition goes away.
20	RESERVED
21	LOGS	Logging stopped	Sets on certain faults	Logging stops until cleared by software	Capture logs, then clear LOGS
22	SHTRIP	Shunt trip (EU only)	Sets when RCCB Residual Current Circuit Breaker shunt trip is activated. Cleared by software.	Shunt trip relevant side.	Note: Port is out of service. Maintenance required. System should clear fault.
23	CHA	Charging Authorized (alias of CHA bit in Port Charge Control Register)	0: charging disabled 1: charging enabled CHA will reset automatically when Pilot status = (State A \| State E \| State F)
31:24	RESERVED

Signed Meter Blob

Byte Stream, containing the signed meter blob at that point in time. This consists of (in order)

Header: 32-bit unsigned integer consisting of
- Unused: 24-bit unused section
- Version: 8-bit version number of the blob
SequenceNumber: 4-byte unsigned integer, containing a monotonically increasing sequence number.
PosEnergy – 8-bytes accumulated delivered positive energy in WattHour, stored in IEEE

double precision of 15 digits
NegEnergy – 8-bytes accumulated delivered negative energy in WattHour, stored in IEEE double precision of 15 digits
PosSumISquared – 8-bytes WattHour/Ohm delivered energy, stored in IEEE double precision of 15 digits
NegativeSumISquared – 8-bytes WattHour/Ohm delivered energy, stored in IEEE double precision of 15 digits
Signature: 512-bit byte stream, containing the ECDSA Elliptic Curve Digital Signature Algorithm secp256k1 signature of the payload

Unsigned Meter Blob

Byte Stream, containing the unsigned meter blob at that point in time. This consists of (in order)

Header: 32-bit unsigned integer consisting of
- Unused: 24-bit unused section
- Version: 8-bit version number of the blob
SequenceNumber: 4-byte unsigned integer, containing a monotonically increasing sequence number.
PosEnergy – 8-bytes accumulated delivered positive energy in WattHour, stored in IEEE double precision of 15 digits
NegEnergy – 8-bytes accumulated delivered negative energy in WattHour, stored in IEEE double precision of 15 digits
PosSumISquared – 8-bytes WattHour/Ohm delivered energy, stored in IEEE double precision of 15 digits
NegativeSumISquared – 8-bytes WattHour/Ohm delivered energy, stored in IEEE double precision of 15 digits
Signature: All 0’s and Unused

Safe Pilot Voltage

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
				Maximum
R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0

15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
				Minimum
R-0	R-0	R-0	R-0	R-0	R-0	R-0	R-0	RW-0	RW-0	RW-0	RW-1	RW-0	RW-0	RW-0	RW-0

Minimum and Maximum are 12 -bit unsigned integers representing the highest and lowest sample values from the Safe Pilot signal. To convert to volts:

V =	Value – 2016.5
	151.4

Sample Buffers

Each sub-item is an array of SAMPLE_BUFFER_SIZE (currently 800) int16 sample values. Samples are stored at the rate determined by the Meter Log Rate Register. Voltages are deciVolts (tenth of a volt) and currents in centiAmps (one-hundredth of an Amp).

Samples are stored in a circular buffer. The current add point index is available in the Meter Sample Buffer – origin object. Note that reading any of the Meter Sample Buffer object will set the LOGS bit in the port status register. This freezes the buffer until the LOGS bit is cleared by software.