PD Sentry Event and Alarm Relay

The alarm and event relayer is built to receive alarms from isolated networks and to forward them to another network of a lower information security classification where monitoring is being performed. No compromising data is transferred between the domains!


  • PD 101 is used for relaying alarms and other events between security domains.
  • PD 101 enables communication from a network with higher information security classification to a system with a lower security classification.
  • Only preconfigured event codes are transferred.
  • One-way communication between two security domains. For example, from a network of a higher information security classification to a network of a lower information security classification.
  • The relayer consists of two separate parts divided by a built-in optical diode link. Unidirectional properties in hardware design ensure unidirectional communication regardless of software.
  • Only approved events are accepted.
  • All data is identified on the receiving side and new messages are generated on the transmitting side. Only preconfigured codes are transferred from the transmitting network to the receiving network, PD 101 shields sensitive information in the transmitting network from the receiving network.
  • No operating system is used – processing is done on basic hardware to minimize the attack vectors and enable a high security level.
  • PD 101 can also be used with Fibersystem Data Diode as a highly controlled back channel for data reception acknowledgement.

Technical Data


  • Connections RJ45x2

Power supply

  • Power consumption 7W


  • Temperature range Operating, +10 till +40 C. Storage, 0 till +70 C
  • Relative humidity Operating, to 95%. Storage, 5 % to 95% – non condensing

Dimensions and Weight

  • Size 115 (H), 20 (W), 195 (D) mm. 4.5 (H), 0.8 (W), 7.7 (D) inch
  • Weight 0.15kg/0.33lbs


  • RFC 1157 SNMP v1
  • RFC 3416 SNMP v2


Associated products