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IEC FLAG is a sub-set of IEC 1107 and is fully compatible with IEC 1107.

IEC 1107 is not FLAG, although sometimes it is incorrectly called so. IEC FLAG includes specifically the optical physical medium of infra-red transmitter, receiver and ring-magnet.

1. Remote (Modem Friendly) FLAG

Remote or Modem Friendly FLAG is a derivative of FLAG suitable for remote access via telephone, or such radio-based systems as Paknet. The only difference between this and IEC FLAG is that it operates at fixed baud rate. Many meter manufacturers have implemented Remote FLAG as a simple extension to IEC FLAG to provide identical access to the meter remotely as well as locally.

2 FLAG 1, or UK FLAG

This protocol formed the basis of the FLAG concept and in essence provides the same functionality (memory read/write access) as IEC FLAG. The differences are mainly the padding characters, checksum derivatives and no defined method for changing the baud rate. FLAG 1 has been superseded by IEC FLAG.

3 Water FLAG

This is an implementation of FLAG via two or three wire inductive loop physical medium, proposed for use in the Water Meter industry . Whilst the medium is different the protocol is identical allowing AMR systems to be designed that read meters from different utilities.

4 Generic FLAG

The generic form of FLAG is shown in the shaded area above. The primary purpose of FLAG is to provide the common denominator for connectivity into utility meters. Many protocols and proposed standards will go into details which additionally affect comunication medium and type and format of data available in the meter. Such proposals have implications not only to the meter manufacturers, but across communication companies, software companies, system integrators involved in Automatic Meter Reading (AMR), and even regulatory bodies at national level. Such standards take years to evolve because so many parties have input. FLAG does not attempt to cover these areas. FLAG will allow manufacturers to develop metering and communication products in parallel with the larger standards and to provide compatible solutions today while the larger standards are still evolving.