Mitsubishi Electric MELSEC iQ-F Series User Manual page 50

Communication specifications
The following table lists the MQTT communication specifications.
Item
MQTT function
MQTT protocol version
Encrypted communication
Key length (client certificate)
Maximum size of Topic
Maximum size of a message to be published
MQTT server address
MQTT server port number
Client ID
User name
Password
*1 Since users enter Unicode strings or ASCII character strings, conversion between Unicode string (UTF-16) and UTF-8 is performed
inside the module.
*2 Strings that meet the following conditions
A+(B+C)2+D984
A: Number of characters in the MQTT server host name
B: Number of characters in the client ID
C: Number of characters in the user name
D: Number of characters in the password
■Encryption algorithms used in TLS communications
The following table lists the encryption algorythms used in TLS communications.
Function name
SSL/TLS support (client and server)
DTLS support (client and server)
Hash function support
Encryption with block, stream, and authentication
Public-key cryptography
Curve type of ECC
Key length of ECC
PSK (pre-shared key)
4 FUNCTION LIST
48
4.3 Other Functions
Specifications
• Connects to the MQTT server (broker).
• Sends messages to the MQTT server as a publisher.
• Receives messages from the MQTT server as a subscriber.
V3.1.1
Available for TLS1.3 and TLS1.2
• 1024 bits
• 2048 bits
• 511 characters (ASCII, excluding NULL character)
• 255 characters (Unicode string, excluding NULL character)
• 32768 bytes (binary)
• 32767 characters (ASCII, excluding NULL character)
• 16383 characters (Unicode string, excluding NULL character)
The IP address or host name (ASCII) can be specified.
Number of characters: One or more characters
1 to 65534
Set it with Unicode strings.
Number of characters: One or more characters
Set it with Unicode strings.
Number of characters: 0 or more characters
Set it with ASCII character strings.
Number of characters: 0 or more characters
Algorithm
TLS 1.2
TLS 1.3
None
SHA-1
SHA-256
SHA-384
SHA-512
AES
RSA
ECDHE-ECDSA
ECDHE-RSA
SECP
SECPR2
SECPR3
256
384
None
*2
*1
*2
*1
*2
*1
*2
CBC
GCM
GMAC
*1
*1