When planning your automation strategy you may want to consider using Analog Input and Digital Input blocks, or Analog Register and Digital Register blocks. All four blocks combine read/write capabilities and eliminate the need for separate output blocks.
Analog Register and Digital Register blocks also have specific addressing and configuration requirements:
- Neither block can cross a poll record boundary.
- You select signal conditioning for an Analog Register block when you configure it. This selection applies to all picture objects associated with the block.
- Offsets to Float or Long data types must be in 2-word (4 byte) increments. This adjusts for the 32-bit word size of these data types.
- Neither block should be used with exception-based poll records.
Although we do not recommend it, if you choose to use Analog Register or Digital Register blocks with exception-based processing, verify that no database block or offset address points to the same address as an exception-based database block. For further information, refer to your I/O driver manual.
If your I/O driver or OPC server supports structured data types (Timers, Counters, etc.), these data types only support an offset of 0 for Analog and Digital registers.
