TagID code is used for three types of messages in OCPP:
Authorize
StartTrans
StopTrans
Format of TagID is not specifically defined, it is only noted that it needs to be a string. At least two vendors are using only HEX format. These are Alfen/ICU and DBT. Alfen/ICU is using 7 byte HEX TagID and DBT is using 4 byte TagID.
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Same problem can occur while in roaming mode. In that case TagID, is even longer than our mobile authentication ID. Examples using the EVCOIDType:
DE-8EO-CAet5e4XY-3
DE*8EO*Aet5e4*3
Consequently, charging stations from mentioned vendors are unable to recognize the TagID. Here the problem with conversion is even greater, as the number of users is larger and will increase rapidly over the next years, meaning that the 7 byte hex code will surely not be the correct future-proof solution.
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