Mitsubishi Electric AE630-SW User manual

MITSUBISHILow-VoltageAirCircuitBreakerstypeAE
Modbus Interface unit (BIF-MD)
INSTRUCTION MANUAL
ACB types covered in this manual
AE630-SW AE1000-SW AE1250-SW AE1600-SW
AE2000-SWA
AE2000-SW AE2500-SW AE3200-SW
AE4000-SWA
AE4000-SW AE5000-SW AE6300-SW
IMPORTANT NOTE: Before using these Series AE breakers, please read these
instructions carefully, and make sure that all actual users also read them.

E-2
●SAFETY PRECAUTIONS ●
Make sure to observe the following matters of safety
Before using the device, make sure to read these safety precautions and instruction manual thoroughly. The cautionary items
noted herein are of the utmost importance for the safe use of this device, and should always be strictly followed.
Make sure that the final user receives this manual.
This instruction manual is prepared for an electrical expert.
The following symbols have been used:
DANGER
Do not use the device on the conditions over range. Failure to do so may result in fire.
Do not touch the terminals. There is a risk of electrical shock.
CAUTION
A qualified electrician should install this equipment.
Make sure to tighten the terminal screws to the torque specified in this manual. Failure to do so may result in malfunction
or fire.
Do not install in areas subject to high temperatures, high humidity, dust, corrosive gas, vibrations, shocks, etc. To do so
may result in malfunction or fire.
Install so that trash, concrete dust, iron filings or rainwater cannot get into the device interior. Failure to do so may result
in malfunction or fire.
CAUTION
Mitsubishi Electric Corporation puts the maximum effort into making electric products better and more reliable, but generally
electric products may incorrect-operate under the influence of a noise etc.
In order not to cause abnormalities to a system by the influence of a noise etc., please retry 3 times or more with master
software in case of error reply or no reply.
DANGER
CAUTION
Failure to follow these instructions
may result in dangerous conditions,
which in turn could lead to severe
personal injury or even death.
Failure to follow these instructions
may result in dangerous conditions,
which could result in moderate to
slight personal injury or damage to
equipment and facilities
This means prohibition. Never ignore
this indication.
Make sure to follow these
instructions without fail.

E-3
■EMC Directive
In IEC60947-2, following EMC tests are required.
1) Radiated radio frequency emission
2) Radiated radio frequency electromagnetic field immunity
BIF-MD shall be installed in the panel board. It effects not only for safe against electric shock but also to interrupt
noise emission from the device. BIF-MD is confirmed to IEC60947-2 in accordance with following conditions.
●Installation
Install the device in power distribution board or control panel board that is made of conductive materials.
Power distribution board and control panel board have to be grounded to the earth with a thick wire of low
impedance.
The frame ground terminal (FG) in the device has to be grounded to the earth with a thick wire of low impedance.
(*grounded resistance: 100 ohm or less).
●Cables
Modbus cable, Internal Transmission cable shall be kept distance more than 100mm from the power distribution
circuit.
However, when parallel installation with the power distribution circuit is required, it is necessary to increase to
300mm.
■Dielectric voltage test
The dielectric voltage test should be executed according to the table below. Do not test in points other than a
following table because unit is damaged.
Measuring point
Condition
Between main circuit and BIF-MD terminals (P1, P2)
2500VAC 1min.
Between main circuit and BIF-MD terminal (FG, Ter, T/R+, T/R-, COM, SLD)
Between BIF-MD terminals (P1, P2) and BIF-MD terminal (FG, Ter, T/R+, T/R-, COM, SLD)
1500VAC 1min.
Between main circuit and BIF-CON terminals (C1, C2, A1, A2, U1 and U2)
2500VAC 1min.
Between BIF-MD terminals (P1 and P2) and BIF-CON terminals (C1, C2, A1, A2, U1 and U2)
1500VAC 1min.
Between BIF-MD terminals (FG, Ter, T/R+, T/R-, COM, SLD)
and BIF-CON terminals (C1, C2, A1, A2, U1 and U2)
BIF-CON terminals (C1 and C2),
BIF-CON terminals (A1 and A2),
BIF-CON terminals (U1 and U2), each other
■Guarantee
The period of guarantee is for 1 year from the sale date except in case of the failure has been caused by bad handling of the
device.

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- Table of Contents -
1. System Overview ･･････････････････････････････････････････････････････････････････････････････････ 5
2. Specifications
2.1 BIF-MD ･･･････････････････････････････････････････････････････････････････････････････････････ 6
2.2 BIF-CON ･･････････････････････････････････････････････････････････････････････････････････････ 7
3. Part Names and Settings
3.1 BIF-MD ･･･････････････････････････････････････････････････････････････････････････････････････ 8
3.2 BIF-CON ･･････････････････････････････････････････････････････････････････････････････････････ 12
4. Installation
4.1 IEC rail installation ･･････････････････････････････････････････････････････････････････････････････ 16
4.2 Bracket installation ･････････････････････････････････････････････････････････････････････････････ 17
5. Modbus Data Format
5.1 Standard frame ････････････････････････････････････････････････････････････････････････････････ 18
5.2 Bit sequence ･･･････････････････････････････････････････････････････････････････････････････････ 18
5.3 Modbus Message RTU Framing ･･････････････････････････････････････････････････････････････････ 18
5.4 Framing of Query and Response ･････････････････････････････････････････････････････････････････ 19
5.5 Modbus Exception Response ････････････････････････････････････････････････････････････････････ 20
5.6 Resister address ････････････････････････････････････････････････････････････････････････････････ 21
6. Outline dimensions ･････････････････････････････････････････････････････････････････････････････････ 33
7. SERVICE NETWORK ･･･････････････････････････････････････････････････････････････････････････････ 34

E-5
BIF-MD (Modbus Interface unit) is used for monitoring and operating ACB with Modbus RTU protocol.
●Monitoring:
- Measurement items (current, voltage, power, harmonics, energy, etc)
- Trip and alarm information (present status, history)
- Breaker status (Breaker ON/OFF status, Position of Breaker (*BIF-CON and BIF-CL is required)).
●Operating:
- Breaker control (ON/OFF/Spring charge). (*CC/SHT/MD and BIF-CON is required.)
- Reset (Trip indicator, Maximum and Minimum measurement, history information).
1. System Overview
-
Modbus
AE-SW
-
RS-232C/RS-485 Converter
Fig 1.1 System Overview
BIF-MD
AE-SW
Internal Transmission cable
BIF-MD
BIF-CON (Option)
*attached to BIF-CON
Wiring for ON/OFF/Spring charge Control
(*User wiring)
BIF-CON is not needed
only in case of
monitoring
measurement items
and trip and alarm
information.
BIF-CON is needed in
case of ON/OFF/Spring
Charge Control.
* attached to BIF-MD

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2.1 BIF-MD
The general specification of BIF-MD is shown in table 2.1.
Table 2.1 General specification of BIF-MD
Item
Specifications
Type name
BIF-MD
Power supply
100-240V AC・DC (50/60Hz)
Power consumption
3VA (not including BIF-CON)
5VA (including BIF-CON)
External dimensions
100(H) x 90(W) x 65(D)
Operating ambient temperature
-5 to +40℃(However, the average of temperature per 24hours must not exceed +35℃)
Storage ambient temperature
-20 to +60℃(However, the average of temperature per 24hours must not exceed +35℃)
Operating/Storage ambient humidity
Max. 85%RH (no condensation) at the max. +40℃in the clean air conditions.
(Do not use and store in corrosive gas atmospheres (e.g. sulfide gas, ammonia gas, etc.)
Operating/Storage ambience
H2S≤0.01ppm, SO2≤0.1ppm, NH3≤0.25ppm
Operating altitude
Max. 2000m (6600ft.)
Installation
35mm IEC rail/Bracket
The functional specifications of BIF-MD are shown in table 2.2.
Table 2.2 Modbus specification of BIF-MD
Item
Specifications
Physical interface
RS-485
Protocol
Modbus RTU mode
Transmission Wiring Type
Multi-point bus (either directly on the trunk cable or forming a daisy-chain)
Baud Rate
2400, 4800, 9600, 19200, 38400 bps (selectable)
Data bit
8
Stop bit
1,2 (selectable)
Parity
Odd, Even, Non (selectable)
Maximum number of unit (without repeater)
31
Range of setting bus address
1 to 127
Response time
500ms or less
Recommended cable
Shielded twisted pair, AWG 24 or wider gauge.
Distance
1000m
Terminate
120Ω(1/2W)
(There is a terminate register in BIF-MD.
In case of the ends of network, connect two Ter. terminals by short wire.)
The setting items specifications of BIF-MD are shown in table 2.3.
Refer to Section 5.6 for details.
Table2.3 Setting items specification of BIF-MD
Item
Setting parameter/range
Setting for shipment
Date & Time
Date
Year：00(2000) to 99(2099),
Month ：01 to 12,
Day：01 to 31
JAN/01/2004
Time
Hour：00 to 23,
Minute：00 to 59,
Second：00 to 59
00:00:00
Demand Time
Load Current (I)
0s to 50s (step: 10s)/
1min to 15min (step: 1min)/
20min/30min
2min
Leakage Current (Ig) 2)
2min
Power (P) 1)
2min
Alarm Hold
Auto Reset/Self-Holding
Auto Reset
earth leakage pre-alarm
(EPAL) 2)
Iep
03) /500mA/600mA/700mA/…/IΔn4)
（Step: 100mA）
0（=OFF）
Tep
100ms/200ms/…/3000ms （Step: 100ms）
3000ms
■1): This cannot be used when VT unit (VT) is not equipped.
■2): These can be available only when the Optional setting module type is E1 (Earth leakage protection).
■3): In case of Iep =0mA, pre-alarm earth leakage function is prohibited.
■4): Iep must be set to IΔn or less.
2. Specifications

E-7
The measurement specifications of BIF-MD are shown in table 2.4.
Refer to Section 5.6 for details.
Table2.4 measurement items specification of BIF-MD
Item
Measurement Range
Unit
Accuracy
Cut off
Load current
0 to 2×In [A]
In < 500A : [0.1A]
In ≥500A : [A]
±2.5% 6)
2.0% 6)
Earth Leakage current 2) 5)
0 to 2×IΔn_max [A]
[0.1A]
±15% 3) 6)
3.0% 6)
Voltage 1) 5)
Line
0 to 725[V]
［V］
±2.5% 6)
10V
Phase
0 to 420[V]
Power 1) 5)
Active
-√3×（2xIn[A]）×725 [V]
to +√3×（2xIn[A]）×725 [V]
In < 1000A : ［0.1kW］
In ≥1000A : ［kW］
±2.5% 6)
2.0% 6)
Reactive
-√3×（2xIn[A]）×725 [V]
to +√3×（2xIn[A]）×725 [V]
In < 1000A : ［0.1kvar］
In ≥1000A : ［kvar］
±2.5% 6)
2.0% 6)
Apparent 4)
0 to +√3×（2xIn[A]）×725 [V]
In < 1000A : ［0.1kVA］
In ≥1000A : ［kVA］
±2.5% 6)
2.0% 6)
Power factor 1) 5) 8)
-50 [%] to 100 [%] to +50 [%]
［0.1%］
±5.0% 6)
-
Energy 1)
Active
0 to 99999999 [kWh]
［kWh］
±2.5% 7)
0.4% 6)
Reactive
0 to 99999999 [kvarh]
［kvarh］
±2.5% 7)
0.4% 6)
Harmonics current 1)
(Max 19th)
RMS
0 to 2×In [A]
In < 500A : [0.1A]
In ≥500A : [A]
±2.5% 6)
2.0% 6)
Distortion
0 to 200 [%]
［0.1%］
-
Frequency 1)
45 to 65 [Hz]
［Hz］
±2.5% 7)
-
Fault current
LTD/STD/INST
0 to 20×In [A]
［10A］
±20% 7)
-
GFR
0 to 2×In [A]
[A]
ER
0 to 2×IΔn_max [A]
［0.1A］
■1): These items cannot be metered when VT unit (VT) is not equipped.
■2): The leakage current metering is available only when the Optional setting module type is E1 (Earth leakage protection).
■3): Include the accuracy of ZCT.
■4): When using at 3φ3W system, the apparent power is calculated by (√3/2)×(I1×V12+ I3×V23).
Therefore, the accuracy may not be ensured in the unbalanced circuit.
■5): Rated voltage of measurement is 440V. Rated power and energy of measurement is √3×In×440V.
Rated earth leakage current of measurement is IΔn_max (=10A). Rated power factor is 90 degrees.
■6): Accuracy and cut off are defined as percentage of rated value.
■7): Accuracy is defined as percentage of true value.
■8): Power factor is measured for only fundamental wave. A waveform distortion is not included for power factor calculation.
2.2 BIF-CON (Option)
The general specifications of BIF-CON are shown in table 2.5.
Table 2.5 General specifications of BIF-CON
■1): SHT (AC380-500V) cannot be used.
Item
Specifications
Type name
BIF-CON
Power supply
Supplied from BIF-MD
Digital input
Number of channel
3 channels (INPUT1, INPUT2, INPUT3, general use)
Isolation
Photo coupler isolation
Signal level
12VDC, 30mA
Digital output
Number of channel
3 channels (*SHT 1)/CC/MD exclusive use)
Isolation
Relay isolation
Contact capacity
8A at 250V AC・DC (resistive load) 1)
External dimensions
100(H) x 90(W) x 65(D)
Operating ambient temperature
-5 to +40℃(However, the average of temperature per 24hours must not exceed +35℃)
Storage ambient temperature
-20 to +60℃(However, the average of temperature per 24hours must not exceed +35℃)
Operating/Storage ambient humidity
max. 85%RH (no condensation) at the max. +40℃in the clean air conditions.
Operating/Storage ambience
Do not use and store in atmospheres with sulfide gas, ammonia gas, etc.
(H2S≤0.01ppm, SO2≤0.1ppm, NH3≤0.25ppm)
Operating altitude
max. 2000m (6600ft.)
Installation
35mm IEC rail/Bracket

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3.１BIF-MD
The unit overview is shown as below.
●(A) LEDs
Name
Indication
Description
Check
POWER
ON
Power is supplied.
OFF
Power is not supplied.
T ERR.
Flashing
Internal transmission fault
Connection of internal transmission cable.
Power supply of Power supply module (P1-P5).
OFF
Normal operating state
RXD
Flashing
Frame reception.
OFF
No reception.
TXD
Flashing
Frame sending.
OFF
No sending.
Modbus ERR.
Flashing
Transmission fault
Setting of Stop bit, Parity, Baud Rate.
Connection of internal transmission cable.
Connection of Modbus cable. Terminator.
Programming (Function code, address, setting data.)
ON
Setting switch fault
Setting of Stop bit, Parity, Baud Rate, Bus address.
OFF
No fault
●(B) RESET Switch
RESET Switch is used to reset the BIF-MD without power off.
After changing the switch while power supply is on, push this switch.
A
B
C
D
E
F
Fig 3.1: Front view
Fig 3.2: Side view
3. Part Names and Settings
G

E-9
●(C) Terminals
Name 1)
Description
Screw 2)
(Tighten torque)
Notes
P1, P2
100-240V AC・DC
M3
(0.5 to 0.6N.m)
Fuse or Circuit Breaker shall be installed in power supply line.
Do not connect to main circuit of breaker directly.
FG
Frame ground
1. This terminal has to be grounded to the protective ground
conductor by a thick wire of low impedance (*ground
resistance: 100 ohm or less).
2. Connect the FG terminal of each BIF-MD independently. If
not use ground independently, use common ground according
to the figure 3.3.
T/R+
RS-485 signal +
For Modbus cable.
T/R-
RS-485 signal -
COM
RS-485 signal GND
In case of two wires cable, no need to use.
SLD
Modbus cable shield
Ter.
Terminator
There is a terminate register in this device.
In case of the ends of network, connect two Ter. terminals by
short wire as shown in figure 3.4.
■1): Terminal assignment is shown in ”6. Outline dimensions” .
■2): These terminals should be connected with wire using crimp-type terminal.
The available crimp-type terminal is shown in figure 3.5.
max. 6mm
Fig 3.5: Crimp-type terminal
Fig 3.4: Short wire in case of ends of network
BIF-MD
Independent ground…Best Common ground…Good Common ground…NG
BIF-MD
BIF-MD
BIF-MD
BIF-MD
BIF-MD
Fig 3.3: Ground connection

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●(D) SWITCH
The setting of switches is effective when power supply is turned ON.
After changing the switch while power supply is on, push RESET switch (see also “(B) RESET switch” ).
<BUS ADDRESS>
The BIF-MD supports the address range from 1 through 127.
The address is set in binary form shown as below sample.
<Stop bit, Parity, Baud RATE>
Setting of stop bit, parity, Baud Rate must correspond with master setting.
STOP bit
SW 1
1 bit
OFF
2 bit
ON
Parity
SW 2
SW 3
NON
OFF
OFF
EVEN
OFF
ON
ODD
ON
ON
B. RATE
SW 4
SW 5
SW 6
2400bps
OFF
OFF
OFF
4800bps
OFF
OFF
ON
9600bps
OFF
ON
OFF
19200bps
OFF
ON
ON
38400bps
ON
OFF
OFF
●(E) Connector for AE-SW internal transmission cable
This connector is used for internal transmission with AE-SW.
Wiring connection is shown as below.
■Note: Only one BIF-MD can be connected to AE-SW.
Sample setting:
ON : 32, 8, 1
OFF: 64, 16, 4, 2
ADDRESS: 32 + 8 + 1 = 41
Fig 3.6: Wiring Connection
Connect to either
upside (labeled I/F-1 ) or
downside (labeled I/F-2 )
*Attached to BIF-MD
Keep distance more than 100mm
from the power distribution circuit.
Hot plugging is not
permitted
Sample setting:
Stop bit : 1 bit
Parity: EVEN
B. RATE: 38400bps
ADDRESS
ON
8
4
1
2
16
32
64
SW
ON
4
5
6
3
2
1
Knob （Black Part）
ON
OFF
Knob （Black Part）
ON
OFF
Do not change the setting of switches with
mechanical pencil. It may cause malfunction by
carbon dust.

E-11
●(F) Connector for I/O unit (BIF-CON) connection
This connector is used for connection to I/O unit (BIF-CON).
Wiring connection is shown as below.
●(G) IEC rail latch
This is used to attach the BIF-MD to a IEC mounting rail.
IEC rail installation is shown in ”4.1 IEC rail installation” .
200mm cable
(Attached to BIF-CON)
BIF-MD
Keep distance more than
100mm from the power
distribution circuit.
Hot plugging is not
permitted
Fig 3.7: Wiring Connection
BIF-CON (option)

E-12
3.2 BIF-CON
The unit overview is shown as below.
●(A) LEDs
Name
Indication
Description
POWER
ON
Power is supplied from BIF-MD correctly
OFF
Power is not supplied
SHT
ON
1a contact for SHT 1) is closed (500ms)
OFF
1a contact for SHT 1) is open
CC
ON
1a contact for CC 2) is closed (500ms)
OFF
1a contact for CC 2) is open
MD
ON
1a contact for MD 3) is closed (5s)
OFF
1a contact for MD 3) is open
INPUT1
ON
INPUT1 signal is ON
OFF
No INPUT1 signal
INPUT2
ON
INPUT2 signal is ON
OFF
No INPUT2 signal
INPUT3
ON
INPUT3 signal is ON
OFF
No INPUT3 signal
■1): SHT is a type name of AE-SW Shunt trip device which open the main contact via remote control.
For details about SHT, please see “AE-SW INSTRUCTION MANUAL” .
■2): CC is a type name of AE-SW Closing coil which close the main contact via remote control.
For details about CC, please see “AE-SW INSTRUCTION MANUAL” .
■3): MD is a type name of AE-SW Motor charging device which charges the closing spring for motor operating.
For details about MD, please see “AE-SW INSTRUCTION MANUAL” .
Fig 3.8: Front view
Fig 3.9: Side view
A
B
C
D
E
F

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●(B) Terminals
Name 1)
Description
Screw 2)
(Tighten torque)
C1, C2 3)
Output terminals for SHT
M3
(0.5 to 0.6N.m)
A1, A2 3)
Output terminals for CC
U1, U2 3)
Output terminals for MD
K12
Digital input1 terminal
K22
Digital input2 terminal
K32
Digital input3 terminal
K11
Input common
■1): Terminal assignment is shown in ”6. Outline dimensions” .
■2): These terminals should be connected with wire using crimp-type terminal.
The available crimp-type terminal is shown in figure 3.10.
■3): These output terminals are exclusive to SHT/CC/MD.
■4): About the remote control via the Modbus network, or local control with
pushbuttons, the sample of user’s wiring with BIF-CON and AE-SW is
shown in figure 3.11.
max. 6mm
Fig 3.10: Crimp-type terminal
Fig 3.11: Sample of user’s wiring
These cables and switches 1)
are required if digital input
functions are used.
(*not attached to BIF-CON)
■1): The switch that can
open and close the
minute load (12V, 30mA)
should be use.
SHT and CC cannot be
driven simultaneously.
These connection cables 1) are required if SHT/CC/MD
are driven by remote control 2).
■1): These cables are not attached to BIF-CON.
Therefore, these should be prepared by the user.
■2): In case of remote control, REMOTE/LOCAL switch
placed on the BIF-CON should be in REMOTE
position. (see also “(C) REMOTE/LOCAL switch” ).
Pushbuttons 1) are required only if SHT/CC/MD are
driven by local operation 2).
■1): Pushbuttons are not attached to BIF-CON.
Therefore, these should be prepared by the user.
■2): In case of local operation by pushbuttons,
REMOTE/LOCAL switch placed on the BIF-CON
should be in LOCAL position for safety.
(see also “(C) REMOTE/LOCAL switch” ).

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●(C) REMOTE/LOCAL switch
The REMOTE/LOCAL switch is used for change over of remote/local control of AE-SW.
When this switch is in REMOTE position, the remote control (ACB ON/OFF and charging the spring) are available via
Modbus network.
When this switch is in LOCAL position, the remote control can not be operated.
●(D) Connector for AE-SW Drawout position switch (BIF-CL) connection
This connector is used for connection to BIF-CL (*Option).
For details about BIF-CL, see “Instruction Manual for AE-SW Drawout position switch” .
Wiring connection is shown as below.
BIF-CL cable
(*Attached to BIF-CL)
Fig 3.12: Wiring Connection
Keep distance more than
100mm from the power
distribution circuit.
Hot plugging is not
permitted

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●(E) Connector for BIF-MD connection
This connector is used for connection to BIF-MD.
Wiring connection is shown as below.
●(F) IEC rail latch
This is used to attach the BIF-CON to a IEC mounting rail.
IEC rail installation is shown in ”4.1 IEC rail installation” .
200mm cable
(*Attached to BIF-CON)
BIF-MD
Keep distance more than
100mm from the power
distribution circuit.
Hot plugging is not
permitted
Fig 3.13 Wiring Connection
BIF-CON (option)

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4.1 IEC rail installation
Installation of BIF-MD and BIF-CON on the 35mm IEC rail (DIN rail) is shown as below.
The applicable IEC rail is shown in figure 4.1.
(A) Installation
(B) Removing
4. Installation
Fig 4.1: 35mm IEC rail
①Hook on the upper side of rail
②Push BIF-MD/BIF-CON into rail until it clicks
①Insert a screwdriver (flathead)
into the hole of IEC rail latch
②Push up a screwdriver
Fig 4.2: Installing
Fig 4.3: Removing

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4.2 Bracket installation
Installation of BIF-MD and BIF-CON with the mounting bracket is shown as below.
Mounting φ4.5 hole
Fig 4.4: Mounting bracket Installation of BIF-MD, BIF-CON
Mounting bracket (Attached to BIF-MD and BIF-CON)

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For details, please download and refer to MODBUS over Serial Line Specification & Implementation guide from the following URL;
http://www.ModBus.org/
5.1 Standard frame
The standard communications frame consists of:
Slave
address
Function
code
data
CRC
Slave address ：01～7FH
*When selecting slave address 0, a message is sent to all the instruments present on the network.
When the slave receives it, the slave does not make a response.
Function code ：03H …… Read Holding Registers ( maximum 250 bytes)
：08H …… Diagnostics
：10H …… Preset Multiple Registers
DATA ：8 bit HEX data
CRC ：The Cyclical Redundancy Check (CRC) field is two bytes, containing a 16–bit binary value.
<NOTE>
A procedure for generating a CRC is:
1. Load a 16–bit register with FFFF hex. Call this the CRC register.
2. Exclusive OR the first 8–bit byte of the message with the low–order byte of the 16–bit CRC register, putting the result in
the CRC register.
3. Shift the CRC register one bit to the right (toward the LSB), zero–filling the MSB. Extract and examine the LSB.
4. (If the LSB was 0): Repeat Step 3 (another shift).
(If the LSB was 1): Exclusive OR the CRC register with the polynomial value 0xA001 (1010 0000 0000 0001).
5. Repeat Steps 3 and 4 until 8 shifts have been performed. When this is done, a complete 8–bit byte will have been
processed.
6. Repeat Steps 2 through 5 for the next 8–bit byte of the message. Continue doing this until all bytes have been processed.
7. The final content of the CRC register is the CRC value.
8. When the CRC is placed into the message, its upper and lower bytes must be swapped as described below.
5.2 Bit sequence
With RTU character framing, the bit sequence is:
＜Example＞With Parity Checking
Start
1
2
3
4
5
6
7
8
Parity
Stop
LSB MSB
＜Example＞Without Parity Checking
Start
1
2
3
4
5
6
7
8
Stop
Stop
LSB MSB
5.3 Modbus Message RTU Framing
A Modbus message is placed by the transmitting device into a frame that has a known beginning and ending point.
This allows devices that receive a new frame to begin at the start of the message, and to know when the message is completed.
Partial messages must be detected and errors must be set as a result.
In RTU mode, message frames are separated by a silent interval of at least 3.5 character times.
The entire message frame must be transmitted as a continuous stream of characters.
If a silent interval of more than 1.5 character times occurs between two characters, the message frame is declared incomplete
and should be discarded by the receiver.
more than 3.5 char less than 1.5 char less than 1.5 char more than 3.5 char
Response
Slave
address
Function
code
CRC(Lo)
CRC(Hi)
Response
5. Modbus Data Format

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5.4 Framing of Query and Response
<Read Holding Registers（Function code : 03H）>
Query framing
**H
03H
Hi
Lo
Hi
Lo
Lo
Hi
Slave
address
Function
Code
Starting address
quantity of registers
CRC
Slave address ：1～7FH
Starting address ：2 bytes
Quantity of registers ：Maximum 125
CRC ：2 bytes
Response framing （Maximum 255 bytes）
**H
03H
Byte
count
Hi
Lo
Hi
Lo
Lo
Hi
Slave
address
Function
Code
data 1
data 2
CRC
Byte count of response data ：maximum 250
＜Example＞In case of monitoring from instantaneous current in Phase 1 （0300H）to apparent power （0326H）.
Slave address ：01H
Query framing
01H
03H
03H
00H
00H
27H
Lo
Hi
Slave
address
Function
Code
Starting address
quantity of registers
CRC
Response framing
01H
03H
4EH
H
L
H
L
H
L
Lo
Hi
Slave
Address
Function
Code
Byte count
I1
I2
Apparent
Power
CRC
<Preset Multiple Registers（Function code :10H）>
Query framing （Maximum 255 bytes）
**H
10H
Hi
Lo
Hi
Lo
Hi
Lo
Hi
Lo
Lo
Hi
Slave
address
Function
Code
Starting
address
quantity of
registers
Byte
count
data 1
data 2
CRC
Slave address ：0～7FH，0 means broadcasting.
Starting address ：2 bytes
quantity of registers ：Maximum 123
Byte count ：Maximum 246
Preset data ：Minimum 2 bytes
CRC ：2 bytes
Response framing （If the slave address is 0 (broadcast), a response is not made.）
**H
10H
Hi
Lo
Hi
Lo
Lo
Hi
Slave
address
Function
Code
starting address
quantity of registers
CRC
＜Example＞In case of setting from Date and time (YYMM) (20EH) to Contact output(211H).
Slave address ：01H
Query framing
01H
10H
02H
0EH
00H
04H
08H
H
L
H
L
H
L
H
L
Lo
Hi
Slave
address
Function
Code
starting
address
quantity of
registers
Byte
count
YY
MM
DD
HH
MM
SS
Contact
Output
CRC
*BCD code
Response framing
01H
10H
02H
0EH
00H
04H
Lo
Hi
Slave
address
Function
Code
starting address
quantity of registers
CRC

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<Diagnostics（Function code :08H）（sub function code 00H）>
This function code is used for initial test of master’s software.
Query framing
**H
08H
00H
00H
Hi
Lo
Lo
Hi
Slave
address
Function
Code
sub function code
data
CRC
slave address ：1～7FH
sub function code ：00H
data ：2 bytes
CRC ：2 bytes
Response framing
**H
08H
00H
00H
Hi
Lo
Lo
Hi
Slave
address
Function
Code
sub function code
data
CRC
data ：same as the data of query
5.5 Modbus Exception Responses
ERROR
Meaning
Exception code
Display
Framing error
Query framing was incorrect.
No response is returned.
Please retry with master
software.
Modbus ERR. LED is
turned ON (flashing) until
receiving the correct query
in case of no error.
Overrun error
1 byte data length was incorrect.
Parity error
1 byte data was incorrect.
CRC error
Framing data were incorrect.
Illegal function
The function code received in the query
was except 03h, 08h and 10h.
01
Illegal data address
The data address received in the query is
not an allowable address for the slave.
02
Illegal data value
The data value received in the query is
not an allowable data for the slave.
03
Slave busy
Slave is busy on initial state or internal
transmission *1 cable is not connected.
06
*1 Addresses 02**h (0209h-02B9h) can be monitored even if internal transmission error has occurred.
Response framing
Slave address
function code *1
Exception code
Lo
Hi
**H
**H
**H
CRC
*1 function code : In an exception response, the server sets the MSB of the function code to 1.
<Example>
function code in a query
function code in an exception response
03h
83h
08h
88h
10h
90h
CAUTION
Mitsubishi Electric Corporation puts the maximum effort into making electric products better and more reliable, but generally
electric products may incorrect-operate under the influence of a noise etc.
In order not to cause abnormalities to a system by the influence of a noise etc., please retry 3 times or more with master
software in case of error reply or no reply.