Chapter 9. Diagnostics444 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C9.6.1 DLB OperationDLBs are created as components of a specific Target and areseparate from the application logic block componentsassociated with a target.They are written in LD programming language and supportmany of the same features, such as View Lock, Edit Lock, etc. asother block types.A target can have a maximum of 128 DLBs in a given PMEtarget. Each DLB can have associated published variable table(PVT) and cam profile (used with Motion applications) files. EachDLB can use up to 128K bytes of memory.A DLB can be copied and pasted like other blocks. Regardless ofwhere a DLB is pasted, normal conflict handling is applied. Figure 22: Diagnostic Logic Blocks(DLBs) assigned to Target in MPEAn active DLB can be dragged to the Toolchest, to folders under the Active Blocks node, or tofolders under the Program Blocks node. Note that only active blocks can be dragged. Downloading,executing, or modifying a DLB does not affect the equality of the main logic program.Suspend I/O Function and DLBsThe Suspend I/O (SUS_IO) function operates the same in a DLB as it does in application logic. Bothapplication logic and DLB logic execute in the CPU Sweep Logic window. Therefore, when aSUSPEND_IO is executed by either the application or the DLB, outputs are held current during theoutput scan that occurs immediately after the Logic window finishes its execution, and inputreferences will not be updated from inputs during the input scan that occurs immediately before theLogic window is executed in the next CPU sweep.Note that a SUSPEND_IO only affects normal I/O scans. It does not affect I/O scanning that is done asthe result of DO_IO or SCAN_SET_IO functions that execute in application or DLB logic. SUS_IO hasthe same effect whether it is executed once in a sweep or multiple times in a sweep.
