Y link

• Transmission rates for the redundant master system:
  9.6 Kbit/s to 12 Mbit/s
• Bumpless switchover of the redundant PROFIBUS DP master system's active channel.
• Supports system changes on a SIMATIC S7-400H during operation
• Diagnostics via LEDs and the user program

Y coupler

• Transmission rates for the lower-level master system (independent of redundant DP master system):
  187.5 Kbit/s to 12 Mbit/s
• Electrical isolation between lower-level DP master system and power supply via the coupler
• IP20 degree of protection

Principle of operation

The Y link maps the lower-level DP master system on the redundant PROFIBUS DP master system as a switched PROFIBUS DP slave .

The Y coupler and the lower-level DP master system form an independent bus system and operate decoupled from the redundant bus system.

The Y link as a DP slave on the redundant DP master system acts as a proxy for the stations on the lower-level DP master system with regard to data.

Configuration

The Y link can be configured with STEP 7 as of Version 5.4. It is not necessary to configure the Y coupler.

When STEP 7 calculates the bus parameters, the stations connected on the lower-level DP master system as well as the Y link itself are taken into account.

Parameter assignment of the DP slaves

The redundant DP master system assigns the parameters for the DP slaves in the lower-level DP master system via the Y link.