Net Address Format

The general form for the channel's SNA consists of 3 separate fields, separated by the * character as follows:

NET * NODE * ADDRESS

 

  1. The address field is the only mandatory field in the SNA. It specifies which point within a single piece of equipment is to be accessed. The format depends upon the equipment vendor's conventions. Generally, a standard Modicon name that identifies a 1-, 16-, or 32-bit data object may be used for this field. There is no default.
  2. The node field specifies which piece of equipment on the NET contains the point to be accessed. It usually consists of a single number, in the range supported by the protocol.
  3. The net field specifies which device port on the RTU provides access to the point. If this field is present, then the node field must also be present, delimited by the * character.