There are two Program Hardware options in the communications menu:
Program Hardware (continue schemas) will attempt to merge together the schema currently running in the device with the schema being downloaded. If the device determines it is possible to complete the merge, there will be a brief pause in schema execution while the merge takes place, then the downloaded schema will continue processing from the state it was in before the merge occurred. During the brief pause, all outputs will hold their state. The 'continue schema' download is useful when performing a program update to a device that is actively controlling a system in a manner that does not upset the system.
The device may determine it is not possible to merge the two schemas together due to lack of memory resources or the differences between the running and downloaded schema are too great. In these cases, Design Pad will indicate it is not possible to merge and prompts to perform a reset schema download instead.
Program Hardware (reset schemas) will erase any program currently running in the device and perform a fresh download. All I/O channels transition to their 'safe state'. Inputs transition to high impedance (for example 4-20mA loop sensors will turn off); outputs deactivate. After the new schema loads, the controller will configure all the I/O as specified in the schema's hardware setup.
During the transmission a Communications window displays the upload's progress (Figure 12.2).
Figure 12.2. Upload Progress
