Structure artobj :
Array
(
    [type] => TLV
    [92] => Array
        (
            [type] => TLV
            [2] => Array
                (
                    [type] => TLV
                    [1] => Array
                        (
                            [type] => V
                            [nom] => IDUS_NUM
                            [format] => 3
                        )

                    [2] => Array
                        (
                            [type] => V
                            [nom] => AID
                            [format] => 3
                        )

                    [3] => Array
                        (
                            [type] => V
                            [nom] => CODPRES
                            [format] => 3
                        )

                    [4] => Array
                        (
                            [type] => V
                            [nom] => TYPPRES
                            [format] => 3
                        )

                    [5] => Array
                        (
                            [type] => V
                            [nom] => DEBCRED
                            [format] => 3
                        )

                    [6] => Array
                        (
                            [type] => V
                            [nom] => DATE_PREST
                            [format] => 3
                        )

                    [7] => Array
                        (
                            [type] => V
                            [nom] => MONTANTHT
                            [format] => 3
                        )

                    [8] => Array
                        (
                            [type] => V
                            [nom] => DEVISE
                            [format] => 3
                        )

                    [9] => Array
                        (
                            [type] => V
                            [nom] => HEUREPREST
                            [format] => 3
                        )

                    [16] => Array
                        (
                            [type] => V
                            [nom] => DEBABO
                            [format] => 3
                        )

                    [17] => Array
                        (
                            [type] => V
                            [nom] => FINABO
                            [format] => 3
                        )

                    [18] => Array
                        (
                            [type] => V
                            [nom] => LibComp
                            [format] => 3
                        )

                    [19] => Array
                        (
                            [type] => V
                            [nom] => SerIpFti
                            [format] => 3
                        )

                    [20] => Array
                        (
                            [type] => V
                            [nom] => TimeZone
                            [format] => 3
                        )

                    [126] => Array
                        (
                            [type] => TLV
                            [16] => Array
                                (
                                    [type] => V
                                    [nom] => DATE_STR
                                    [format] => 26
                                )

                        )

                )

        )

)

Exemple : 
$t[92][2][126][16] TLV =Array
(
    [type] => V
    [nom] => DATE_STR
    [format] => 26
)