3.5 How to Program and Configure Different Networks

SimpleCAN requires at least one node to act as master on the bus. All Safety Simplifier nodes are potential masters if they have at least one TX block. The Simplifier Gateway cannot act as master. This means that every network needs at least one Safety Simplifier that sends at least one SimpleCAN ID.

Note

SimpleCAN requires at least one Simplifier node to be a master.

Note

The SimpleCAN network settings (baud rate, cycle time, timeout) must be identical in all projects that share the network.

Note

A SimpleCAN ID can only be used once in a network (two nodes cannot send the same SimpleCAN ID).

Note

In each physical Simplifier node on SimpleCAN, the maximum number of TX + RX blocks in total is 64.

Note

In each SimpleCAN network, the maximum number of TX blocks is 64.

3.5.1 SimpleCAN blocks for sending and receiving data

Simplifier Manager is used to configure units to send and receive SimpleCAN data. Use SimpleCAN RX blocks to receive data and SimpleCAN TX blocks to transmit data. Each RX and TX block has 16 safe bits (CM01–CM16) and 16 unsafe bits (CM17–CM32, shown on the block as NS_CM01–NS_CM16). The unsafe bits can be used for information and other tasks that do not require redundant safety.

The SimpleCAN ID is set in the block itself, and each ID can only be used once in a network: two nodes cannot send the same SimpleCAN ID. IDs range from SC01 to SC64, so up to 64 different IDs can exist in one network.

A data bit is identified by the block ID (SC01–SC64) and the data number (CM01–CM32).

Figure 3.1: RX and TX blocks in Simplifier Manager.

Since each Simplifier node can handle up to 64 IDs, the maximum total number of TX + RX blocks for each node is 64. Examples of possible usage of SimpleCAN IDs for one Safety Simplifier node:

• 64 SimpleCAN TX blocks and 0 SimpleCAN RX blocks
• 63 SimpleCAN TX blocks and 1 SimpleCAN RX block
• 62 SimpleCAN TX blocks and 2 SimpleCAN RX blocks
• 0 SimpleCAN TX blocks and 64 SimpleCAN RX blocks (in this case the node cannot act as master on the bus)

Each Simplifier can handle up to 1024 bits of safety data (any combination of sending and receiving) and 1024 bits of unsafe data (any combination of sending and receiving).

Warning

Only the safe bits (CM01–CM16) can be used for safety functions. The unsafe bits are colored white in Simplifier Manager, like all other unsafe signals (see 1.7.17 Safe and unsafe logic).

3.5.2 Configuring SimpleCAN networks

The project CAN configuration decides which nodes communicate using SimpleCAN. This is also where ProfiNET gateways are configured.

Each Gateway can handle up to two SimpleCAN networks: one network on CAN 1 and one network on CAN 2. More SimpleCAN networks can be added by adding more Gateways.

To configure a SimpleCAN network, go to Project → CAN Configuration in the main menu.

Figure 3.2: Opening the CAN configuration from the Project menu.

In the dialog that is shown, you can:

• Add and remove networks: click Add new network, or click the red cross next to a network to remove it.
• Update network parameters: open the Network parameters tab. Here you set the baud rate, network name, description, cycle time (CycleTimeMs) and timeout (TimeoutMs).
• Update node settings and assign a node to a SimpleCAN network: click the node and use the General or Network settings tab. The Can0NetworkID setting selects which network the node belongs to.
• Add a Gateway: click the plus sign under the Gateway heading.

Figure 3.3: How to configure SimpleCAN networks.

Choosing cycle time and timeout

Use 3.3.2 Calculating maximum reaction time to pick values for CycleTimeMs and TimeoutMs. The default network in Figure 3.3 uses 20 ms cycle time and 45 ms timeout (2 × 20 + 5).

3.5.3 Simplifier Gateway

See the user manual for the Simplifier Gateway.