Appendix C: Modbus Communication

Communication Protocol

Data exchange between a PC and the UBZ-302M is done in MODBUS RTU packets. The data packet format is described in Table 2.1.

Table 2.1 - Data packet format

Field	Description
START	silence interval – over 4 ms at 9 600, or over 2 ms at 19 200 baud
ADR	UBZ-302M communication address (8 bits)
FUNCTION	Command code (8 bits)
DATA 0 … DATA (n-1)	Data contents: N×8 data bits (n<=24)
CRC CHK low	CRC checksum (16 bits)
CRC CHK high
END	silence interval – over 4 ms at 9 600 baud, or over 2 ms at 19 200 baud

Communication Parameters

Parameter	Setting	Description
Address (Add)	1-247	Device network address
Baud Rate (bdS)	9600/19200	Communication speed
Data Format	8N2	8 data bits, no parity, 2 stop bits

MODBUS Interface Command Codes (FUNCTION and DATA)

The format of data character depends on command codes.

Function Code	Description
0x03	Read Holding Registers
0x04	Read Input Registers
0x06	Write Single Register
0x08	Diagnostics

Command code 0x03, reading n words

Note

While performing one command there could be read not more than 12 registers (n=12).

Example: reading 2 words continuously starting from the address 100 (0x0064) in the UBZ-302M with communication address 0x01.

Command Message		Response Message
ADR	0x01	ADR	0x01
FUNCTION	0x03	FUNCTION	0x03
Data start address	0x00, 0x64	Data amount, bytes	0x04
Data amount, words	0x00, 0x02	Data contents at address	0x17, 0x70
CRC CHK low	0x85	Data contents at address	0x00, 0x00
CRC CHK high	0xD4	CRC CHK low	0xFE
		CRC CHK high	0x5C

Command code 0x06, writing one word

Caution

Using this command is not recommended, because writing incorrect data may result in UBZ-302M failure.

Data can only be written using the addresses of programmable parameters (see Table 1.5), except the parameters listed in Table 2.3.

Table 2.3 - Parameters that cannot be written via MODBUS

Set and Read Parameters	Code Parameters	Address
Total device uptime, days	tbU	207
Motor uptime, days	tCO	208
User access code	LOC	209
Engineer access code	PA5	210
Reset to factory parameters	PPP	211
Device version	rEL	217

The parameter is written regardless of any engineer protection set (writing via the communication line has a higher priority).

When a new value is written into a MMSP-protected cell, the parameter is automatically excluded from the MMSP mode.

The parameters being written must be a multiple of the interval specified in Table 1.5.

Example: writing the entry 1000 (0x03E8) into the register at the address 160 (0x00A0), in the UBZ-302M with the communication address 0x01.

Command Message		Response Message
ADR	0x01	ADR	0x01
FUNCTION	0x06	FUNCTION	0x06
Data start address	0x00, 0xA0	Data start address	0x00, 0xA0
Data	0x03, 0xE8	Data	0x03, 0xE8
CRC CHK low	0x89	CRC CHK low	0x89
CRC CHK high	0x56	CRC CHK high	0x56

Command code 0x08 – diagnostics

The 0x08 function provides for a number of tests used to check the communication between the PC and the UBZ-302M, and to check the UBZ-302M operational state. The function uses the sub-function field to elaborate the action (test).

Sub-function 0x00 – return query data

The data sent in the data field of the query must be returned in the data field of the response.

Example: sub function 0x00 request and response in UBZ-302M with communication address 0x01.

Command message		Response message
ADDRESS ID	0x01	ADR	0x01
FUNCTION	0x08	CMD	0x08
Subfunction	0x00, 0x00	Subfunction	0x00, 0x00
Data	0xA0, 0x3C	Data	0xA0, 0x3C
CRC CHK low	0x98	CRC CHK low	0x98
CRC CHK high	0x1A	CRC CHK high	0x1A

Sub-function 0x01 – restart communication options

While performing the command only the change of communication speed is carried out in UBZ-302M. For total change of communication parameters it is necessary to initiate the command “UBZ RESTART” (“RESTART”) (see Command Register).

Example: sub function 0x01 request (response is not returned) for UBZ-302M with communication address 0x01.

Command message
ADDRESS ID	0x01
FUNCTION	0x08
Subfunction	0x00, 0x01
Data	0x00, 0x00
CRC CHK low	0xB1
CRC CHK high	0xCB

CRC – Cyclic Redundancy Check

The checksum (CRC16) is a cyclical checking code based on the 0xA001 polynomial. The transmitter creates a checksum for all bytes of the transmitted message. The receiver creates the checksum for all bytes of the received message and compares it to the checksum received from the transmitted. If the created and received checksums are not the same, an error message is generated.

The checksum field occupies two bytes. In a message, the checksum is transmitted least significant byte first.

The following algorithm is used to create the checksum:

1. load CRC register (16 bit) with ones (0xFFFF);
2. XOR gate with the first 8 bits of the message byte and the contents of the CRC register;
3. shift result one bit to the right;
4. if the shifted bit = 1, XOR gate with the register contents with value of 0xA001;
5. if the shifted bit = 0, repeat step 3;
6. repeat steps 3, 4, 5, until 8 shifts are carried out;
7. XOR gate with the next 8 bits of the message byte and the contents of the CRC register;
8. repeat steps 3-7 until all bytes of the message are processed;
9. the final contents of the register will contain the checksum.

An example of CRC generating code in C. The function receives two arguments:

• unsigned char* data – indicator to message buffer;
• unsigned char length – number of bytes in the buffer.

The function returns the CRC value as (unsigned int).

unsigned int crc_chk(unsigned char* data, unsigned char length)
{
    int j;
    unsigned int reg_crc = 0xFFFF;
    while(length--)
    {
        reg_crc ^= *data++;
        for(j = 0; j < 8; j++)
        {
            if(reg_crc & 0x01)
                reg_crc = (reg_crc >> 1) ^ 0xA001;  // LSB(b0)=1
            else
                reg_crc = reg_crc >> 1;
        }
    }
    return reg_crc;
}

Communication Error Processing

In case of an error during frame reception (parity error, frame error, checksum error), UBZ-302M returns no response.

In case of an error in format or value of transmitted data (unsupported function code, etc.), UBZ-302M accepts the query frame and creates a response containing the error indication code. The error indication is the 1 in the higher bit of the function field. A separate field is reserved for the error code in the response.

Example: function 0x30 error response (illegal function) from UBZ-302M with communication address 0x01.

Command message		Response message
ADDRESS ID	0x01	ADR	0x01
FUNCTION	0x30	FUNCTION ERROR	0xB0
DATA	…	Error code	0x01
CRC CHK low	…	CRC CHK low	0x94
CRC CHK high	…	CRC CHK high	0x00

Table 2.6 - Error codes

Error code	Name	Description
0x01	ILLEGAL FUNCTION	The UBZ-302M cannot process the accepted function code
0x02	ILLEGAL DATA ADDRESS	The data address in the query is not accessible by this slave device
0x03	ILLEGAL DATA VALUE	The value in the query data field is not acceptable for the UBZ-302M
0x04	SLAVE DEVICE FAILURE	An unrecoverable error occurred when UBZ-302M tried to carry out the requested action
0x05	ACKNOWLEDGE	The UBZ-302M accepted the query, but processing it requires a long time. This response prevents the master device from generating a timeout error
0x06	SLAVE DEVICE BUSY	The UBZ-302M is busy processing the command. The master device should resent the message later, when the slave device is free
0x07	NEGATIVE ACKNOWLEDGE	The UBZ-302M cannot carry out the program function contained in the query

Measured Parameters (Input Registers, Table 1.4)

Current Parameters

Parameter	Mnemonic	Address	Range	Units	Accuracy
Phase 1 current	iF1	100	0.5-630	0.1A	2%
Phase 2 current	iF2	101	0.5-630	0.1A	2%
Phase 3 current	iF3	102	0.5-630	0.1A	2%
Zero sequence current	iF0	103	0.3-5.0	0.1A	2%
Phase 1 average current	iS1	104	-	0.1A	-
Phase 2 average current	iS2	105	-	0.1A	-
Phase 3 average current	iS3	106	-	0.1A	-
Phase 1 max average	in1	107	-	0.1A	2%/10%
Phase 2 max average	in2	108	-	0.1A	2%/10%
Phase 3 max average	in3	109	-	0.1A	2%/10%
Starting current	iPU	110	-	0.1A	2%/10%
Start time	tPU	111	0.1-600	s	-
Overcurrent	iPE	112	-	0.1A	2%/10%
Negative sequence current	ioP	113	0.2-200	0.1A	5%

Note

When using external CTs with rated current over 100A, current values (except zero sequence) are transferred in A instead of 0.1A units.

Voltage Parameters

Parameter	Mnemonic	Address	Range	Units	Accuracy
Phase 1 voltage	UF1	114	100-300	V	3V
Phase 2 voltage	UF2	115	100-300	V	3V
Phase 3 voltage	UF3	116	100-300	V	3V
Line voltage U12	UL1	117	100-475	V	5V
Line voltage U23	UL2	118	100-475	V	5V
Line voltage U31	UL3	119	100-475	V	5V
Positive sequence voltage	UPP	120	100-300	V	3V
Negative sequence voltage	UP	121	3-300	V	3V
Zero sequence voltage	UnP	122	3-100	V	3V

Note

• Zero sequence voltage (vector sum of three phase voltages, divided by three) measurement is possible only when zero wire is connected to UBZ-302M.

Temperature and Analog Inputs

Parameter	Mnemonic	Address	Range	Units	Accuracy
Temperature sensor 1	td1	123	-40 to 100	°C	1°C
Temperature sensor 2	td2	124	-40 to 220	°C	1°C
4-20mA input	in1	125	0-25	0.01mA	2%
0-10V input	inU	126	0-10	0.1V	2%

Note

• If the temperature value exceeds the specified limit, the value indicator displays an error code as per Table 2.8.

Temperature sensor status codes:

• 5000: Sensor not connected.
• 1000±10: Sensor short-circuited.
• 2000±10: Sensor fault.

Miscellaneous Parameters

Parameter	Mnemonic	Address	Range	Units	Accuracy
Operation time	Str	127	0-999	days	-
Frequency	FFF	128	45-65	0.1Hz	1%
Time to thermal trip	tOP	129	0-600	s	1s
ARC countdown	tAP	130	0-900	s	1s
Thermal wait time	ttP	131	0-900	s	1s
Insulation resistance	rid	132	0-19.9	0.1MΩ	10%
Motor thermal balance	-	133-134	0-100000	0.001%	-

Note

• If the time is not defined, --- is displayed on screen.
• If protection operation or automatic reclosing is forbidden, not is displayed.
• If automatic reclosing is forbidden, not message is displayed.
• If the motor insulation resistance exceeds 20 MOhm, the code 1_ is displayed (numerical “one” with a point in the higher digit).
• When the power voltage is supplied to the motor, the insulation resistance is not defined, and --- code is displayed.

Power Parameters

Parameter	Mnemonic	Address	Range	Units	Accuracy
Total power	Pot	135-136	0-5000	10W	5%
Active power	PoA	137-138	0-5000	10W	5%
Reactive power	PoJ	139-140	0-5000	10VAr	5%
Phase A cos φ × 1000	-	141-142	0-1000	-	5%
Phase B cos φ × 1000	-	143-144	0-1000	-	5%
Phase C cos φ × 1000	-	145-146	0-1000	-	5%

Note

• If the power consumed by the load exceeds 999 kW (kVA, kVAr), then the MW (MVA, MVAr) value is displayed on screen with a n – shaped point in the middle digit. For example, if the display shows 3n4, it means 3.4 MW (MVA, MVAr).

Programmable Parameters (Table 1.5)

Current Transformer Settings

Parameter	Mnemonic	Address	Min	Max	Default	Description
CT type	tPt	150	0	1	0	0=Internal, 1=External CT
CT rated current	tnt	151	20	800	100	External CT primary current (A)
Motor rated current	ind	152	0	630	0	Nominal motor current (A)
Average measurement time	tS1	153	10	600	60	Time for average current (s)

Overcurrent Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Protection type	i⁼P	154	0	5	0	0=Independent, 1=SIT, 2=VIT, 3=EIT, 4=UIT, 5=RI
Tripping ratio	i⁼5	155	0.8	9.0	4.0	Multiplier × rated current
Tripping delay	i⁼t	156	0.3	600	10.0	Time delay (s)
Permission	i⁼r	157	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
Priority vs thermal	i⁼n	158	0	1	1	0=Independent, 1=After thermal

Ground Fault Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Tripping threshold	i_5	159	0.3	5.0	0.5	Ground fault current (A)
Tripping delay	i_t	160	0.3	2.0	1.0	Time delay (s)
Permission	i_r	161	0	2	2	0=Off, 1=On no ARC, 2=On with ARC

Negative Sequence Current Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Tripping threshold	io5	162	5	20	10	% of rated current
Tripping delay	iot	163	0.3	10.0	5.0	Time delay (s)
Permission	ior	164	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
K2i/K2u ratio	iO5	165	2	4	2	Threshold ratio
Analysis enable	iOr	166	0	1	1	0=Off, 1=On

Thermal Overload Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Permission	dtr	167	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
Double overload time	dtt	168	10	120	60	Trip time at 2× current (s)
Cooling time ratio	dtP	169	1.0	4.0	1.0	Stopped motor cooling factor

Undercurrent Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Tripping threshold	i₌5	170	11	90	20	% of rated current
Tripping delay	i₌t	171	1	100	5	Time delay (s)
Permission	i₌r	172	0	2	2	0=Off, 1=On no ARC, 2=On with ARC

Delayed Start / Rotor Blocking Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Tripping ratio	PP5	173	1.5	7.0	5.0	Multiplier × rated current
Start time delay	PPt	174	1	600	10	Motor start time (s)
Blocking delay	Pbt	175	0.3	300	1.0	Rotor blocking delay (s)
Permission	PPr	176	0	2	1	0=Off, 1=On no ARC, 2=On with ARC

Voltage Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Minimum voltage	U₌5	177	270	415	320	Undervoltage threshold (V)
Min voltage delay	U₌t	178	5	30	10	Time delay (s)
Min voltage permission	U₌r	179	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
Maximum voltage	U⁼5	180	330	475	415	Overvoltage threshold (V)
Max voltage delay	U⁼t	181	1	10	2	Time delay (s)
Max voltage permission	U⁼r	182	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
Voltage imbalance	Uⁿ5	183	15	120	35	Negative sequence threshold (V)
Imbalance delay	Uⁿt	184	1	30	5	Time delay (s)
Imbalance permission	Uⁿr	185	0	2	2	0=Off, 1=On no ARC, 2=On with ARC
Phase sequence permission	UЧr	186	0	2	1	0=Off, 1=On no ARC, 2=On with ARC

ARC (Automatic Reclosing) Settings

Parameter	Mnemonic	Address	Min	Max	Default	Description
ARC time (undercurrent)	Atn	187	0	900	600	Delay after undercurrent (s)
ARC time	Att	188	0	900	5	Standard ARC delay (s)
ARC permission	Arr	189	0	1	1	0=Forbidden, 1=Allowed
Start after power-on	APd	190	0	2	1	0=Manual, 1=After ARC, 2=2s delay
Panel control	ACd	191	0	3	0	0=Off, 1=Start, 2=Stop, 3=Both

Temperature Control

Parameter	Mnemonic	Address	Min	Max	Default	Description
Sensor 1 type	C1r	192	0	2	0	0=Off, 1=Integrated, 2=PTC
Sensor 1 trip temp	C1S	193	0	100	80	De-energize temperature (°C)
Sensor 1 correction	C1c	194	-9	9	0	Temperature offset (°C)
Sensor 2 type	C2r	195	0	3	0	0=Off, 1=Pt100, 2=Ni100, 3=Ni120
Sensor 2 trip temp	C2S	196	0	220	180	De-energize temperature (°C)
Sensor 2 warning temp	C2A	197	0	220	170	Warning temperature (°C)
Sensor 2 correction	C2c	198	-9	9	0	Temperature offset (°C)
ARC after temp trip	CPA	199	1	2	2	1=No ARC, 2=ARC allowed
Sensor failure reaction	CCr	200	0	1	0	0=Warning, 1=Stop motor

Insulation Monitoring

Parameter	Mnemonic	Address	Min	Max	Default	Description
Insulation protection	rid	201	0	20	5	See description below

Insulation Protection Settings:

• 0: Protection off
• 5: No start if <500kΩ, ARC allowed
• 10: No start if <1MΩ, ARC allowed
• 15: No start if <500kΩ, no ARC
• 20: No start if <1MΩ, no ARC

Display and Mode Settings

Parameter	Mnemonic	Address	Min	Max	Default	Description
MMSP mode	5in	202	0	1	1	0=On, 1=Off
Display before start	5iP	203	0	2	1	0=Voltage, 1=Insulation, 2=ARC
Parameter display mode	5iC	204	0	1	1	0=Continuous, 1=15s timeout
Functional relay mode	rr5	205	0	2	0	0=Signal, 1=Timer, 2=Star-delta
Timer delay	rrt	206	0	300	30	Functional relay delay (s)

Operation Counters

Parameter	Mnemonic	Address	Min	Max	Default	Description
Device uptime	tbU	207	0	999	0	Total operation time (days)
Motor uptime	tCO	208	0	999	0	Motor run time (days)

Security Settings

Parameter	Mnemonic	Address	Min	Max	Default	Description
User password	LOC	209	0	9	0	0=Unlocked, 1-9=Password
Engineer password	PA5	210	0	999	123	000=Unlocked, else=Password
Factory reset	PPP	211	0	1	0	Set 1 to reset

Serial Interface Parameters

Parameter	Mnemonic	Address	Min	Max	Default	Description
Device address	rSA	212	1	247	1	MODBUS address
Baud rate	rSS	213	0	1	0	0=9600, 1=19200
Link loss reaction	rSP	214	0	3	0	See description below
Timeout detection	rSO	215	0	120	0	Link timeout (s), 0=Off
Interface selection	rPP	216	0	2	0	0=Off, 1=USB, 2=RS-485
Device version	rEL	217	-	-	22	Read-only

Link Loss Reaction (rSP):

• 0: Continue operation, no warning
• 1: Warning, continue operation
• 2: Warning, stop motor, ARC after restore
• 3: Warning, stop motor, no ARC

Star-Delta Mode

Parameter	Mnemonic	Address	Min	Max	Default	Description
Switching time	Ftt	218	0.1	2.0	0.4	Time between star and delta (s)

Phase Loss Protection

Parameter	Mnemonic	Address	Min	Max	Default	Description
Trip delay	ibt	219	0.3	10	0.5	Phase loss delay (s)
Permission	ibr	220	0	2	1	0=Off, 1=On no ARC, 2=On with ARC

Remote Control

Parameter	Mnemonic	Address	Min	Max	Default	Description
Remote control	dUd	221	0	2	0	0=Off, 1=On+auto start, 2=On+manual start

Analog Input Control (0-20mA)

Parameter	Mnemonic	Address	Min	Max	Default	Description
Upper threshold	Ait	222	0	20.0	10.0	High threshold (mA)
Lower threshold	Aib	223	0	20.0	1.0	Low threshold (mA)
Control algorithm	AiA	224	0	2	0	0=Off, 1=Stop on high, 2=Start on high
Fault logging	AiE	225	0	1	0	0=No log, 1=Log faults

Analog Input Control (0-10V)

Parameter	Mnemonic	Address	Min	Max	Default	Description
Upper threshold	AUt	226	0	10.0	5.0	High threshold (V)
Lower threshold	AUb	227	0	10.0	1.0	Low threshold (V)
Control algorithm	AUA	228	0	2	0	0=Off, 1=Stop on high, 2=Start on high
Fault logging	AUE	229	0	1	0	0=No log, 1=Log faults

External Contact

Parameter	Mnemonic	Address	Min	Max	Default	Description
External MS control	CCi	230	0	1	1	0=Off, 1=On

Remote Motor Control and Command Register

Remote control of the UBZ-302M is determined by the value of dUd.

At dUd=0, remote control of the motor is forbidden.

At dUd=1, the UBZ-302M operation after energizing is the same as with remote control off (regular operation), but writing into the R_COMMAND command register is allowed.

At dUd=2, the UBZ-302M will energize the motor only after a respective command is received via the USB/RS-485 interface.

The value of R_COMMAND is taken into consideration by the UBZ-302M operation algorithm at dUd=1 and dUd=2. If dUd=0, and the user sets dUd=1 or dUd=2, “0” will be written to R_COMMAND.

At dUd=1, “1” will be written into the command register after power on (regular operation). At dUd=2, “0” will be written into the command register after power on (the motor is switched off until the energize command is given).

After emergency de-energizing of the motor by simultaneous pressing of UP and DOWN (at ACd=2 or ACd=3), the command register will be reset to 0.

Table 2.7 - Command codes

Command register R_COMMAND (Address = 237)	Actions
0	De-energize motor. If the motor is off, it will not be energized until a remote energize command is given. If the motor is on, it will be de-energized.
1	Regular device operation. If the motor was de-energized by a remote command, or by simultaneous pressing of UP and DOWN (at ACd=3), or by a fault with permitted subsequent ARC, then after 1 is written into R_COMMAND, the motor will be energized after the ARC time delay.
2	Early motor de-energizing. Writing 2 into R_COMMAND results in the motor energizing before the end of the ARC time delay. After the motor is on, R_COMMAND = 1.
55 (0x37)	Command “UBZ ALARMS RESET”
88 (0x58)	Command “UBZ RESTART” (“RESTART”)

De-energize the motor command

If the motor is on, writing the 1 to R_COMMAND will de-energize it.

If the motor is off, it will not be energized until a remote energize command (1 or 2) is given.

Regular device operation command

If the motor was de-energized by a remote command, or by simultaneous pressing of UP and DOWN (at ACd=3), or by a fault with permitted subsequent ARC, then after 1 is written into R_COMMAND, the motor will be energized after the ARC time delay.

Early motor re-energizing command

Writing 2 into R_COMMAND results in:

• the motor energizing before the end of the ARC time delay.
• after the motor is on, R_COMMAND will be set to 1 (regular operation).

Command “UBZ ALARMS RESET”

The command “UBZ ALARMS RESET” is to be initiated after entering the command code 55 in command register (Table 2.7) by interface USB/RS-485.

While initiating the command:

• the alarms are being reset no matter whether the ARC is disabled or enabled (except for the current alarms on engine currents availability at the load relay being deactivated CCi and alarm of EEPROM destruction);
• ahead of time counting of ARC ends and, if there are no new alarms, the engine starts.

Command “UBZ RESTART” (“RESTART”)

The command “UBZ RESTART” is used for initiating the changed communication parameters. The command “UBZ RESTART” is to be initiated after entering the command code 88 in command register (Table 2.7) by interface USB/RS-485. After receiving the command “UBZ RESTART” UBZ-302M does not return the confirmation of received command.

Note

Between the last addressing to registers UBZ-302M and entering the command “UBZ RESTART” there should be a time delay not less than 100 msec.

Warning

Do not execute the “UBZ RESTART” command (88) while the motor is running.

Status and Fault Registers

Device Status Register (Address 240)

Bit	Description
0	0=No fault, 1=Fault active (fault code in register 241)
1	0=Load relay open, 1=Load relay closed
2	0=Functional relay open, 1=Functional relay closed
3	0=No restart pending, 1=ARC expected
5-4	Functional relay mode: 00=signaling relay; 01=time relay; 10=star / delta
6	0=MMSP off, 1=MMSP on
7	0=regular operating mode; 1=UBZ-302M in hysteresis area when working with analog inputs

Fault Registers

Address	Description
241	Fault register 1 (bits 0-15, according to Table 2.8)
242	Fault register 2 (bits 0-10, according to Table 2.8)

Fault Log

Description	Address	Purpose
Fault code 1	243	fault code according to Table 2.8
Parameter value 1	244	parameter value according to Table 2.8
Fault time 1 (high word)	245	two upper bytes
Fault time 1 (low word)	246	two lower bytes
Fault code 2	247	see register 243
Parameter value 2	248	see register 244
Fault time 2 (high word)	249	see register 245
Fault time 2 (low word)	250	see register 246
Fault code 3	251	see register 243
Parameter value 3	252	see register 244
Fault time 3 (high word)	253	see register 245
Fault time 3 (low word)	254	see register 246
Fault code 4	255	see register 243
Parameter value 4	256	see register 244
Fault time 4 (high word)	257	see register 245
Fault time 4 (low word)	258	see register 246
Fault code 5	259	see register 243
Parameter value 5	260	see register 244
Fault time 5 (high word)	261	see register 245
Fault time 5 (low word)	262	see register 246

Note

• Alarm time is a time period spent from the moment of initiation of power supply to UBZ-302M till the moment of alarm taking place. It is measured in minutes.
• The default alarm code 40 and parameter value 10000 is stored in the alarm registers initially.
• The number 5000000 is written to all alarm time registers at power-up.

Fault Codes (Table 2.8)

Code	Bit	Register	Mnemonic	Description	Parameter Address
0	0	241	Ai⁼	Phase overcurrent	300
1	1	241	Adt	Thermal overload	301
2	2	241	Ai_	Ground fault	302
3	3	241	AiO	Excess K2i/K2u	303
4	4	241	Aio	Negative sequence current	304
5	5	241	Ai₌	Phase undercurrent	305
6	6	241	APP	Delayed start	306
7	7	241	APb	Rotor blocking	307
8	8	241	At1	Temperature sensor 1	308
9	9	241	At2	Temperature sensor 2	309
10	10	241	AUЧ	Phase sequence	310
11	11	241	ACo	External MS	311
12	12	241	AU₌	Undervoltage	312
13	13	241	AU⁼	Overvoltage	313
14	14	241	AUⁿ	Voltage imbalance	314
15	15	241	Ari	Insulation resistance	315
16	0	242	AdU	Remote channel fault	-
17	1	242	EAd	Emergency stop no ARC	-
18	2	242	EOd	Emergency stop with ARC	-
19	3	242	ES1	Sensor 1 short circuit	-
20	4	242	EO1	Sensor 1 breakout	-
21	5	242	ES2	Sensor 2 short circuit	-
22	6	242	EO2	Sensor 2 breakout	-
23	7	242	EiU	Phase loss	-
24	8	242	EEP	EEPROM destruction	-
25	9	242	AAi	0-20mA input fault	325
26	10	242	AAU	0-10V input fault	326

Resetting of the UBZ-302M factory settings via MODBUS interface

For initiation of this operation it is necessary to set the parameter PPP=1. At this operation the parameters of serial interface will not be changed (the reset of interface parameters to the factory ones is not made). The time period of reset to the factory settings is up to 5 seconds. After the completion of operation the parameter is PPP=0.

Warning

ATTENTION! IT IS FORBIDDEN TO MAKE A RESET TO THE FACTORY SETTINGS VIA MODBUS INTERFACE WITH ENGINE BEING IN OPERATION.

Warning

IT IS FORBIDDEN TO ENTER THE PARAMETERS VIA MODBUS INTERFACE UNTIL THE COMPLETION OF RESET OPERATION.