IEC 60870-5-104, Slave

The IEC 60870-5-104, Slave implements the controlled station functionality specified in the IEC 60870-5-104 protocol. The implementation corresponds to the IEC 60870-5-104 second edition 2006-6. It has been exhaustively tested and certified to comply with the standard by KEMA. See below for the testing certificate and report.

The IEC 60870-5-104, Slave protocol stack offers almost the full functional range of the IEC 60870-5-104 protocol. The supported features:

• Simultaneous and independent communication with several control stations through the same port
• Communication with redundant control systems and interruption-free switchover between redundant systems
• Supports redundant networks
• Bi-directional data transmission (B marking in the interoperability list), this means that indications, measured values, commands etc. can be transmitted in both directions - from control station (master) to slave and vice versa
• Supports "select-before-operate" or "direct-execute" command execution modes
• Largely supports RTUs that do not fully comply with the second edition of the IEC 60870-5-104 standard

The following security enhancements according to the protocol specific standard IEEE 1815-2012 are implemented into the protocol stack IEC 60870-5-104, Slave:

• IEC 62351-3: encryption of ASDU telegrams using TLS protocol with X.509 certificates to protect the transport layer. The TLS versions 1.0, 1.1 and 1.2 are supported. Version 3 of the X.509 certificates must be available. These certificates may contain RSA, DSA and ECC keys. The configuration enables renegotiation of the cryptographic parameters on a condition (time / data / number of telegrams), data size limitation of the remote station certificate, minimum size of asymmetric keys, several certification authorities to check the remote station certificate and an extendable list of encryption procedures supported.

The standard IEC 60870-5-7 was derived from the norm IEC 62351 that applies to a range of protocols and describes messages and data formats for secure authentication especially for the protocols IEC 60870-5-101, IEC 60870-5-104 and IEC 61850.