Networked eDAQXR units can be connected in a variety of ways. See eDAQXR EXRCPU getting started for general information about connection of an EXRCPU to other devices.
Networking Modes: There are two modes that will be supported. Mode 1 is the only mode that is currently supported. Mode 2 will be provided in a future release.
Mode 1 Networking
One eDAQXR serves as the networked system host (subsequently referred to as the master node), and all other connected eDAQXR units provide source data to the master node (subsequently referred to as slave nodes). The master node is not defined in the SXR setup file. When the user starts a test on any network node, that node becomes the master node. This allows the user to experiment with CPU load balancing which is discussed later.
The master node is always used to start the test. The master node runs the test engine that processes all input channels, Computed channels and DataModes and drives the run time displays. A single SIE file is generated on the master node only.
For the most part, the user only needs to communicate with the master eDAQXR. However, there is currently the following exception.
All test runs modes (Normal, Cyclic and Remote control) are available in a networked system. If the Remote control run mode is used, the EXRCPU IO switch 1 on the master node must be used.
Mode 2 Networking
The primary difference between Mode 1 and Mode 2 is that every node runs a test engine and generates an SIE file. This mode will typically only be used when Mode 1 cannot be used due to CPU processing limitations on the master node, or when there is insufficient SIE file storage space on the master node. When support for Mode 2 is released, there will be an SXR test configuration option to specify the desired mode.
Physical Connection Options: These options are completely independent of the option to use Mode 1 or Mode 2 networking.
Connections with no EX23-R switch: A maximum of three eDAQXR units can be connected.
Connections using one or more EX23-R switches: There is no restriction on how many eDAQXR nodes can be connected.
CPU load balancing (Mode 1): For many applications, the user does not need to be concerned with this issue. However, if the average CPU load of any node exceeds 50%, the user should consider options for balancing the CPU loads across the nodes, which may require some trial and error experimentation. Following are some guidelines.