Data Mapping for Modbus Function Code 3 with Unit ID 100
Original instructions
Function Code 3
Some module diagnostics (I/O connection, extended health, redundancy status, FDR server, etc.) are available to Modbus clients that read the local Modbus server area. Use Modbus function code 3 with the unit ID set to 100 for register mapping:
Type
Offset Modbus Address
Size (Words)
Basic Networks Diagnostic Data
0
39
Ethernet Port Diagnostic Data
39
103
Modbus TCP/Port 502 Diagnostic Data
554
114
Modbus TCP/Port 502 Connection Table Data
668
515
SMTP Diagnostic Data
1183
130
SNTP Diagnostic Data
1313
43
DNP/IEC Connection Information
1356
6
DNP/IEC Server/Slave Connection Diagnostic
1362
1141
DNP/IEC Client/Master Connection Diagnostic
2503
1281
DNP Server/Slave Security Diagnostic
3784
157
DNP Client/Master Security Diagnostic
4097
2497
Clock Diagnostic
6750
13
Basic Networks Diagnostic Data
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Basic network diagnostic validity
Offset + 1
MS Byte
LS Byte
Offset + 2
MS Byte
LS Byte
Communication global status
Offset + 3
MS Byte
LS Byte
Supported communication services
Offset + 4
MS Byte
LS Byte
Status of communication services
Offset + 5
IP 1
IP 2
IP address
Offset + 6
IP 3
IP 4
Offset + 7
SN mask 1
SN mask 2
Subnet mask
Offset + 8
SN mask 3
SN mask 4
Offset + 9
GW IP 1
GW IP 2
Default gateway
Offset + 10
GW IP 3
GW IP 4
Offset + 11
MAC 00
MAC 01
MAC address
Offset + 12
MAC 02
MAC 03
Offset + 13
MAC 04
MAC 05
Offset + 14
MS Byte 00
01
Ether frame format capability / configuration / operational
Offset + 15
02
03
Offset + 16
04
LS Byte 05
Offset + 17
C00
C01
Ethernet receive frames OK
Offset + 18
C02
C03
Offset + 19
C00
C01
Ethernet transmit frames OK
Offset + 20
C02
C03
Offset + 21
MS Byte
LS Byte
Number open client connections
Offset + 22
MS Byte
LS Byte
Number open server connections
Offset + 23
C00
C01
Number of Modbus error messages sent
Offset + 24
C02
C03
Offset + 25
C00
C01
Number of Modbus messages sent
Offset + 26
C02
C03
Offset + 27
C00
C01
Number of Modbus messages received
Offset + 28
C02
C03
Offset + 29
Char 1
Char 2
Device name
Offset + 30
Char 3
Char 4
Offset + 31
Char 5
Char 6
Offset + 32
Char 7
Char 8
Offset + 33
Char 9
Char 10
Offset + 34
Char 11
Char 12
Offset + 35
Char 13
Char 14
Offset + 36
Char 15
Char 16
Offset + 37
MS Byte 00
01
IP assignment mode capability / operational
Offset + 38
02
LS Byte 03
Ethernet Port Diagnostic Data
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Port diagnostics data validity
Offset + 1
MS Byte
LS Byte
Logical/physical port number
Offset + 2
MS Byte
LS Byte
Ether control capability
Offset + 3
MS Byte
LS Byte
Link speed capability
Offset + 4
MS Byte
LS Byte
Ether control configuration
Offset + 5
MS Byte
LS Byte
Link speed configuration
Offset + 6
MS Byte
LS Byte
Ether control operational
Offset + 7
MS Byte
LS Byte
Link speed operational
Offset + 8
MAC 00
MAC 01
Port MAC address
Offset + 9
MAC 02
MAC 03
Offset + 10
MAC 04
MAC 05
Offset + 11
MSB - C00
C01
Media counters data validity
Offset + 12
C02
LSB - C03
Offset + 13
MSB - C00
C01
Number frames transmitted OK
Offset + 14
C02
LSB - C03
Offset + 15
MSB - C00
C01
Number frames received OK
Offset + 16
C02
LSB - C03
Offset + 17
MSB - C00
C01
Number Ether collisions
Offset + 18
C02
LSB - C03
Offset + 19
MSB - C00
C01
Carrier sense errors
Offset + 20
C02
LSB - C03
Offset + 21
MSB - C00
C01
Number Ether excessive collisions
Offset + 22
C02
LSB - C03
Offset + 23
MSB - C00
C01
CRC errors
Offset + 24
C02
LSB - C03
Offset + 25
MSB - C00
C01
FSC errors
Offset + 26
C02
LSB - C03
Offset + 27
MSB - C00
C01
Alignment errors
Offset + 28
C02
LSB - C03
Offset + 29
MSB - C00
C01
Number internal MAC transmit errors
Offset + 30
C02
LSB - C03
Offset + 31
MSB - C00
C01
Late collisions
Offset + 32
C02
LSB - C03
Offset + 33
MSB - C00
C01
Number internal MAC transmit errors
Offset + 34
C02
LSB - C03
Offset + 35
MSB - C00
C01
Multiple collisions
Offset + 36
C02
LSB - C03
Offset + 37
MSB - C00
C01
Single collisions
Offset + 38
C02
LSB - C03
Offset + 39
MSB - C00
C01
Deferred transmissions
Offset + 40
C02
LSB - C03
Offset + 41
MSB - C00
C01
Frames too long
Offset + 42
C02
LSB - C03
Offset + 43
MSB - C00
C01
Frames too short
Offset + 44
C02
LSB - C03
Offset + 45
MSB - C00
C01
SQE test error
Offset + 46
C02
LSB - C03
Offset + 47
MS Byte
LS Byte
Interface label length
Offset + 48
IL_char64
IL_char63
Interface label characters
Offset + ...
...
...
Offset + 79
IL_char2
IL_char1
Offset + 80
MS Byte
LS Byte
Interface counters diagnostic validity
Offset + 81
MSB - C00
C01
Number octets received
Offset + 82
C02
LSB - C03
Offset + 83
MSB - C00
C01
Number unicast packets received
Offset + 84
C02
LSB - C03
Offset + 85
MSB - C00
C01
Number non-unicast packets received
Offset + 86
C02
LSB - C03
Offset + 87
MSB - C00
C01
Number inbound packets discard
Offset + 88
C02
LSB - C03
Offset + 89
MSB - C00
C01
Number inbound packets error
Offset + 90
C02
LSB - C03
Offset + 91
MSB - C00
C01
Number inbound packets unknown
Offset + 92
C02
LSB - C03
Offset + 93
MSB - C00
C01
Number octets sent
Offset + 94
C02
LSB - C03
Offset + 95
MSB - C00
C01
Number unicast packets sent
Offset + 96
C02
LSB - C03
Offset + 97
MSB - C00
C01
Number non-unicast packets sent
Offset + 98
C02
LSB - C03
Offset + 99
MSB - C00
C01
Number outbound packets discard
Offset + 100
C02
LSB - C03
Offset + 101
MSB - C00
C01
Number outbound packets error
Offset + 102
C02
LSB - C03
Offset + 103
Port 2
103 words per port
Offset + 206
Port 3
103 words per port
Offset + 309
Port 4
103 words per port
Modbus TCP/Port 502 Diagnostic Data
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Modbus TCP/Port 502 diagnostic data validity
Offset + 1
MS Byte
LS Byte
Offset + 2
MS Byte
LS Byte
Port 502 status
Offset + 3
MS Byte
LS Byte
Number open connections
Offset + 4
MSB - C00
C01
Number Modbus messages sent
Offset + 5
C02
LSB - C03
Offset + 6
MSB - C00
C01
Number Modbus messages received
Offset + 7
C02
LSB - C03
Offset + 8
MS Byte
LS Byte
Number Modbus open client connections
Offset + 9
MS Byte
LS Byte
Number Modbus open server connections
Offset + 10
MS Byte
LS Byte
Maximum number connections
Offset + 11
MS Byte
LS Byte
Maximum number client connections
Offset + 12
MS Byte
LS Byte
Maximum number server connections
Offset + 13
MSB - C00
C01
Number Modbus error messages sent
Offset + 14
C02
LSB - C03
Offset + 15
MS Byte
LS Byte
Number open priority connections
Offset + 16
MS Byte
LS Byte
Maximum number priority connections
Offset + 17
MS Byte
LS Byte
Number entries in unauthorized table
Offset + 18
MSB - IP1
IP2
Remote IP address 1
Offset + 19
IP3
LSB - IP4
Offset + 20
MS Byte
LS Byte
Number attempts to open unauthorized connection 1
...
Offset + 111
MSB - IP1
IP2
Remote IP address 32
Offset + 112
IP3
LSB - IP4
Offset + 113
MS Byte
LS Byte
Number attempts to open unauthorized connection 32
Modbus TCP/Port 502 Connection Table Data
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Connection table validity
Offset + 1
MS Byte
LS Byte
Number of entries
Offset + 2
MS Byte
LS Byte
Starting entry index
Offset + 3
MS Byte
LS Byte
Connection index
Offset + 4
IP 1
IP 2
Remote IP address
Offset + 5
IP 3
IP 4
Offset + 6
MS Byte
LS Byte
Remote port number
Offset + 7
MS Byte
LS Byte
Local port number
Offset + 8
MS Byte
LS Byte
Number Modbus messages sent on Connex
Offset + 9
MS Byte
LS Byte
Number Modbus messages received on Connex
Offset + 10
MS Byte
LS Byte
Number Modbus error messages sent on Connex
SMTP Diagnostic Data
Address
MS Byte
LS Byte
CIP Type
Comments
Offset
MS Byte
LS Byte
UDINT
SMTP server IP address
Offset + 1
MS Byte
LS Byte
Offset + 2
MS Byte
LS Byte
UDINT
Email service status
Offset + 3
MS Byte
LS Byte
Offset + 4
MS Byte
LS Byte
UDINT
Link to SMTP server status
Offset + 5
MS Byte
LS Byte
Offset + 6
MS Byte
LS Byte
UDINT
Number of emails sent
Offset + 7
MS Byte
LS Byte
Offset + 8
MS Byte
LS Byte
UDINT
Number of responses from the server
Offset + 9
MS Byte
LS Byte
Offset + 10
MS Byte
LS Byte
UDINT
Number of errors
Offset + 11
MS Byte
LS Byte
Offset + 12
MS Byte
LS Byte
UDINT
Last error
Offset + 13
MS Byte
LS Byte
Offset + 14
SenderAddress[0]
SenderAddress[1]
ARRAY of octets
Last email header used
Offset + 15
SenderAddress[2]
SenderAddress[3]
...
Offset + 45
SenderAddress[62]
SenderAddress[63]
Offset + 46
SenderAddress[0]
SenderAddress[1]
Offset + 47
SenderAddress[2]
SenderAddress[3]
...
Offset + 109
SenderAddress[126]
SenderAddress[127]
Offset + 110
MailSubject[0]
MailSubject[1]
Offset + 111
MailSubject[2]
MailSubject[3]
...
Offset + 125
MailSubject[30]
MailSubject[31]
Offset + 126
MSW - MSB
MSW - LSB
DINT
Time elapsed from the last email
Offset + 127
LSW - MSB
LSW - LSB
Offset + 128
MSW - MSB
MSW - LSB
UDINT
Number of time server was not reachable
Offset + 129
LSW - MSB
LSW - LSB
SNTP Diagnostic Data
Address
MS Byte
LS Byte
CIP Type
Comments
Offset
MSW - MSB
MSW - LSB
UDINT
Enabled/disabled
Offset + 1
LSW - MSB
LSW - LSB
Offset + 2
MSW - MSB
MSW - LSB
UDINT
Primary NTP server IP address
Offset + 3
LSW - MSB
LSW - LSB
Offset + 4
MSW - MSB
MSW - LSB
UDINT
Secondary NTP server IP address
Offset + 5
LSW - MSB
LSW - LSB
Offset + 6
Unused
LS Byte
USINT
Polling period
Offset + 7
Unused
LS Byte
USINT
Daylight saving auto adjustment
Offset + 8
Unused
LS Byte
USINT
Update CPU with module time
Offset + 9
Unused
LS Byte
USINT
Reserved
Offset + 10
MSW - MSB
MSW - LSB
UDINT
Time zone
Offset + 11
LSW - MSB
LSW - LSB
Offset + 12
MS Byte
LS Byte
INT
Time zone offset
Offset + 13
Unused
Unused
USINT
Reserved
Offset + 14
Unused
Unused
USINT
Reserved
Offset + 15
Unused
LS Byte
USINT
Daylight saving start date - month
Offset + 16
Unused
LS Byte
USINT
Daylight saving start date - week #, day of week
Offset + 17
Unused
LS Byte
USINT
Daylight saving end date - month
Offset + 18
Unused
LS Byte
USINT
Daylight saving end date - week #, day of week
Offset + 19
MSW - MSB
MSW - LSB
UDINT
Network time service status
Offset + 20
LSW - MSB
LSW - LSB
Offset + 21
MSW - MSB
MSW - LSB
UDINT
Link to NTP server status
Offset + 22
LSW - MSB
LSW - LSB
Offset + 23
MSW - MSB
MSW - LSB
UDINT
Current NTP server IP address
Offset + 24
LSW - MSB
LSW - LSB
Offset + 25
MSW - MSB
MSW - LSB
UDINT
NTP server IP address
Offset + 26
LSW - MSB
LSW - LSB
Offset + 27
MSW - MSB
MSW - LSB
UDINT
NTP server time quality
Offset + 28
LSW - MSB
LSW - LSB
Offset + 29
MSW - MSB
MSW - LSB
UDINT
Number of NTP requests sent
Offset + 30
LSW - MSB
LSW - LSB
Offset + 31
MSW - MSB
MSW - LSB
UDINT
Number of communication errors
Offset + 32
LSW - MSB
LSW - LSB
Offset + 33
MSW - MSB
MSW - LSB
UDINT
Number of NTP responses received
Offset + 34
LSW - MSB
LSW - LSB
Offset + 35
MS Byte
LS Byte
UINT
Last error
Offset + 36
MSW - MSB
MSW - LSB
UDINT
Current time
Offset + 37
LSW - MSB
LSW - LSB
Offset + 38
MS Byte
LS Byte
Current date
Offset + 39
MSW - MSB
MSW - LSB
UDINT
Daylight savings status
Offset + 40
LSW - MSB
LSW - LSB
Offset + 41
MSW - MSB
MSW - LSB
UINT
Time since last update
Offset + 42
LSW - MSB
LSW - LSB
DNP/IEC Connection Information
Address
MS Byte
LS Byte
Comments
Offset
Client
Connected
Count
Client
Configured
Count
DNP3/IEC Client
Count
Offset + 1
Server
Connected
Count
Server
Configured
Count
DNP3/IEC Server
Count
Offset + 2
Reserved
Offset + 3
Reserved
Offset + 4
Reserved
Offset + 5
Reserved
DNP/IEC Server/Slave Connection Diagnostic
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Number of entries
Offset + 1
MS Byte
LS Byte
MS byte: Event USED/CONFIGURED 0-100%
LS byte: CONFIGURED/TOTAL 0-100%
Offset + 2
MSB - C03
C02
Module total
Configured event buffer size
Offset + 3
C01
LSB - C00
Offset + 4
MSB - C03
C02
Module total
Current event buffer used
Offset + 5
C01
LSB - C00
Offset + 6
MSB - C03
C02
Module total current overflow
Offset + 7
C01
LSB - C00
Offset + 8
MS Byte
LS Byte
MS Byte: Event buffer overflow
LS Byte: Event backup status
Offset + 9
MS Byte
LS Byte
Channel index
Offset + 10
MS Byte
Reserved
LS Byte
1: DNP3 serial
3: DNP3 NET
5: IEC 101
7: IEC 104
Protocol:
DNP3 serial slave
DNP3 NET server
IEC 101 slave
IEC 104 server
Offset + 11
MS Byte
LS Byte
LS Byte connection state
0: disconnected
1: connected
2: connecting
MS Byte authentication type
0: none
1: SAv2
2: SAv5
3: TLS_ONLY
4: TLS_SAv2
5: T:LS_SAv5
Offset + 12
Char 1
Char 2
Channel name
Offset + 13
Char 3
Char 4
Offset + 14
Char 5
Char 6
Offset + 15
Char 7
Char 8
Offset + 16
Char 9
Char 10
Offset + 17
Char 11
Char 12
Offset + 18
Char 13
Char 14
Offset + 19
Char 15
Char 16
Offset + 20
IP 1
IP 2
Remote IP address
Offset + 21
IP 3
IP 4
Offset + 22
MS Byte
LS Byte
Remote port number
Offset + 23
MS Byte
LS Byte
Local port number
Offset + 24
MS Byte
LS Byte
Error code
Offset + 25
C03
C02
Channel total
Configured event buffer size
Offset + 26
C01
C00
Offset + 27
C03
C02
Channel total
Current event buffer used
Offset + 28
C01
C00
Offset + 29
C03
C02
Channel total
Current overflow
Offset + 30
C01
C00
Offset + 31
MS Byte
LS Byte
MS Byte: reserved
LS Byte: event buffer overflow
Offset + 32
MS Byte
LS Byte
Reserved 1
Offset + 33
MS Byte
LS Byte
Reserved 2
Offset + 34
MS Byte
LS Byte
Reserved 3
Offset + 35
MS Byte
LS Byte
Number of data type
Event status
Always 16
Offset + 36
MS Byte
LS Byte
MS Byte
Bit 0: validity
Bit 1: event buffer overflow
LS Byte: index
Offset + 37
MS Byte
LS Byte
DNP data type:
1. Binary input
2. Double input
3. Binary output
4. Binary counter
5. Frozen counter
6: Analog input
7. Analog output
8-16. For extended
IEC data type:
1. M_SP
2. M_DP
3. M_ST
4. M_BO
5. M_ME_A
6. M_ME_B
7. M_ME_C
8. M_IT
9. Custom_M_IT_D
10-16. For extended
Offset + 38
Char 1
Char 2
Data type name
Offset + 39
Char 3
Char 4
Offset + 40
Char 5
Char 6
Offset + 41
Char 7
Char 8
Offset + 42
Char 9
Char 10
Offset + 43
Char 11
Char 12
Offset + 44
Char 13
Char 14
Offset + 45
Char 15
Char 16
Offset + 46
C03
C02
Configured event buffer size
Offset + 47
C01
C00
Offset + 48
C03
C02
Current event buffer used
Offset + 49
C01
C00
Offset + 50
C03
C02
Current event buffer used
Offset + 51
C01
C00
Current overflow
DNP/IEC Client/Master Connection Diagnostic
Address
MS Byte
LS Byte
Comments
Offset
MS Byte
LS Byte
Number of entries
Offset + 1
MS Byte
LS Byte
Channel index
Offset + 2
MS Byte
Reserved
LS Byte
2: DNP3 serial
4: DNP3 NET
6: IEC 101
8: IEC 104
Protocol:
DNP3 serial master
DNP3 NET client
IEC 101 master
IEC 104 client
Offset + 3
MS Byte
LS Byte
LS Byte connection state:
0: disconnected
1: connected
2: connecting
MS Byte
Offset + 4
Char 1
Char 2
Channel name
Offset + 5
Char 3
Char 4
Offset + 6
Char 5
Char 6
Offset + 7
Char 7
Char 8
Offset + 8
Char 9
Char 10
Offset + 9
Char 11
Char 12
Offset + 10
Char 13
Char 14
Offset + 11
Char 15
Char 16
Offset + 12
IP 1
IP 2
Remote IP address
Offset + 13
IP 3
IP 4
Offset + 14
MS Byte
LS Byte
Remote port number
Offset + 15
MS Byte
LS Byte
Local port number
Offset + 16
Bit 15-8
Bit 7-0
Error code
Bit 0: authentication failed
Bit 1: unexpected response
Bit 2: no response
Bit 3: aggressive mode not supported
Bit 4: MAC algorithm not supported
Bit 5: key wrap algorithm not supported
Bit 6: authorization failed
Bit 7: update key change method not permitted
Bit 8: invalid signature
Bit 9: invalid certification data
Bit 10: unknown user
Bit 11:max session key status requests exceed
Bit 12-15: reserved
Offset + 17
MS Byte
LS Byte
Reserved 0
Offset + 18
MS Byte
LS Byte
Reserved 1
Offset + 19
MS Byte
LS Byte
Reserved 2
Offset + 20
MS Byte
LS Byte
Reserved 3
DNP Server/Slave Security Diagnostic
Address
MS Byte
LS Byte
Comments
Offset
Number of entries
Offset + 1
MS Byte reserved
LS Byte channel index
Channel index
Offset + 2
C03
C02
Unexpected messages
Offset + 3
C01
C00
Offset + 4
C03
C02
Authorization failures
Offset + 5
C01
C00
Offset + 6
C03
C02
Authentication failures
Offset + 7
C01
C00
Offset + 8
C03
C02
Reply timeout
Offset + 9
C01
C00
Offset + 10
C03
C02
Re-keys due to authentication failure
Offset + 11
C01
C00
Offset + 12
C03
C02
Total message sent
Offset + 13
C01
C00
Offset + 14
C03
C02
Total messages received
Offset + 15
C01
C00
Offset + 16
C03
C02
Critical message sent
Offset + 17
C01
C00
Offset + 18
C03
C02
Critical message received
Offset + 19
C01
C00
Offset + 20
C03
C02
Discarded messages
Offset + 21
C01
C00
Offset + 22
C03
C02
Error message sent
Offset + 23
C01
C00
Offset + 24
C03
C02
Error message transmitted
Offset + 25
C01
C00
Offset + 26
C03
C02
Successful authentications
Offset + 27
C01
C00
Offset + 28
C03
C02
Session key changes
Offset + 29
C01
C00
Offset + 30
C03
C02
Failed session key changes
Offset + 31
C01
C00
Offset + 32
C03
C02
Update key changes
Offset + 33
C01
C00
Offset + 34
C03
C02
Failed update key changes
Offset + 35
C01
C00
Offset + 36
C03
C02
Re-keys due to restart
Offset + 37
C01
C00
Offset + 38
C01
C00
Current user number
Offset + 39
C01
C00
Reserved
DNP Client/Master Security Diagnostic
Address
MS Byte
LS Byte
Comments
Offset
Number of entries
Offset + 1
Reserved
Channel index
Offset + 2
C03
C02
Unexpected messages
Offset + 3
C01
C00
Offset + 4
C03
C02
Authorization failures
Offset + 5
C01
C00
Offset + 6
C03
C02
Authentication failures
Offset + 7
C01
C00
Offset + 8
C03
C02
Reply timeout
Offset + 9
C01
C00
Offset + 10
C03
C02
Re-keys due to authentication failure
Offset + 11
C01
C00
Offset + 12
C03
C02
Total message sent
Offset + 13
C01
C00
Offset + 14
C03
C02
Total messages received
Offset + 15
C01
C00
Offset + 16
C03
C02
Critical message sent
Offset + 17
C01
C00
Offset + 18
C03
C02
Critical messages received
Offset + 19
C01
C00
Offset + 20
C03
C02
Discarded messages
Offset + 21
C01
C00
Offset + 22
C03
C02
Error message sent
Offset + 23
C01
C00
Offset + 24
C03
C02
Error message transmited
Offset + 25
C01
C00
Offset + 26
C03
C02
Successful authentications
Offset + 27
C01
C00
Offset + 28
C03
C02
Session key changes
Offset + 29
C01
C00
Offset + 30
C03
C02
Failed session key changes
Offset + 31
C01
C00
Offset + 32
C03
C02
Update key changes
Offset + 33
C01
C00
Offset + 34
C03
C02
Failed update key changes
Offset + 35
C01
C00
Offset + 36
C03
C02
Rekeys due to restart
Offset + 37
C01
C00
Offset + 38
C01
C00
Current user number (1-65535)
Offset + 39
C01
C00
Reserved
Clock Diagnostic
Address
MS Byte
LS Byte
Comments
Offset
Number of entries
Offset + 1
MS Byte reserved
LS Byte clock status
1: Synchronized
0: Unsynchronized
Clock status
Offset + 2
C03
C02
Current time
Offset + 3
C01
C00
Offset + 4
C01
C00
Current date
Offset + 5
Reserved
Offset + 6
C03
C02
Time zone
Offset + 7
C01
C00
Offset + 8
C03
C02
Time of last time synchronization
Offset + 9
C01
C00
Offset + 10
C01
C00
Date of last time synchronization
Offset + 11
Reserved
Offset + 12
MS Byte reserved
LS Byte time source
1: SNTP
2: DNP3
Time source of last time synchronization