Introduction

The CIP Safety DTM, created with or without a vendor EDS file, presents safety connection nodes. Both safety input and safety output nodes are supported, according to the features of a specific device. The Connection tab presents the connection parameters for the selected input connection or output connection.

For DTMs created with a vendor EDS file, default connections are pre-selected. You can use the Remove Connection and Add Connection commands to adapt the connection settings to your application’s requirements.

Safety Input Connection Settings

Each safety input connection presents the following parameters:

• Input Size (Read-Write): The size of input data configured in the CIP Safety device, in bytes. Set to 0 by default.

  NOTE: You need to replace the default value with vendor provide settings. The value 0 is not supported.

• Requested Packet Interval (Read-Write): RPI represents the connection refresh period. Set equal to the (SAFE task period)/2 by default.

  NOTE: The SAFE task period (Tsafe) is set in the Properties of SAFE dialog ( Project Browser > Tasks > SAFE > Properties ) in Control Expert.

• Network_Time_Expectation (Read-Write): The time, in milliseconds, consumed by CIP safety communication. If the value is less than the Minimum Network_Time_Expectation, a detected error notification is displayed. By default, the value should be equal to Minimum Network_Time_Expectation * 1.5.

• Timeout_Multiplier (Read-Write): A component in producing the Minimum Network_Time_Expectation, the Timeout_Multiplier equals the Network_Time_Expectation /128 μSec. The Minimum Network_Time_Expectation = RPI * Timeout_Multiplier + Tsafe + 40.

• Network_Transmission_max (Read-Write): The worst case (oldest) age (in ms) of the data at the time when the packet is received by the consumer. This parameter is used only for calculating the minimum value to be entered into the Network_Time_Expectation (as described below). It can be refined by checking the value of Max-data_age in the consumer device after executing network CIP Safety communication for a significant period of time.

  This parameter is used in the calculation of the minimum value for parameter “Network Time Expectation” as follows:

  Min (Network Time Expectation) = RPI * Timeout_multiplier + Network_Transmission_max

  When Tsafe is modified, the value of this parameter should change and, consequently, the minimum value of Network_Time_Expectation also should change.

  The following attributes apply to this parameter:

  • Minimum value = 1- ms

  • Maximum value: = 5800 ms

  • Default value = 40 + Tsafe

The device DTM uses these input settings to make the following calculations:

Safety Output Connection Settings

Each safety output connection presents the following parameters:

• Output Size (Read-Write): The size of output data configured in the CIP Safety device, in bytes. Set to 0 by default.

  NOTE: You need to replace the default value with vendor provide settings. The value 0 is not supported.

• Requested Packet Interval (Read Only): RPI represents the connection refresh period. Set equal to the SAFE task (Tsafe) period.

• Network Time Expectation (Read-Write): The time, in milliseconds, consumed by CIP safety communication. If the value is less than the Minimum Network_Time_Expectation, a detected error notification is displayed. By default, the value should be equal to Minimum Network_Time_Expectation * 1.5.

• Timeout Multiplier (Read-Write): A component in producing the Minimum Network_Time_Expectation, the Timeout Multiplier equals the Network_Time_Expectation /128 μSec. The Minimum Network_Time_Expectation = RPI * Timeout_Multiplier + Tsafe + 40.

• Network_Transmission_max (Read-Write): The worst case (oldest) age (in ms) of the data at the time when the packet is received by the consumer. This parameter is used only for calculating the minimum value to be entered into the Network_Time_Expectation (as described below). It can be refined by checking the value of Max-data_age in the consumer device after executing network CIP Safety communication for a significant period of time.

  This parameter is used in the calculation of the minimum value for parameter “Network Time Expectation” as follows:

  Min (Network Time Expectation) = RPI * Timeout_multiplier + Network_Transmission_max

  When Tsafe is modified, the value of this parameter should change and, consequently, the minimum value of Network_Time_Expectation also should change.

  The following attributes apply to this parameter:

  • Minimum value = 1- ms

  • Maximum value: = 5800 ms

  • Default value = 40 + 2*Tsafe

The device DTM uses these output settings to make the following calculations: