Click here to go to the Main Page!Support : Support Documents : H-Board Counter

This is to inform you " Caution in using High Speed Counter of H-Board " High Speed Counter of H-board rarely causes miscount (+256 at down counting or -256 at up counting based on applications). Please refer an attached sheet and pay attention to the cautions. Current H-Board has this caution sheet in a carton box. We will send copies of the sheet and would like you to distribute them to your customers who already have H-board.

Best regards

Hitachi Europe GmbH

Cautions in using a high speed counter function

About the high speed counter function of H series board type , counter may rarely miscount in below conditions. Pay attention to the following points in using the high speed counter function of H-board.

In case of using high speed counter under 1kHz, it works without problem.
In case of using high speed counter over 1kHz, refer to the below table.


FUN74 is "High speed counter preset data write".

(Note 3) Set a preset data 0080H with FUN74 even though FUN74 is not used in a user program.