static const char range_codes_pci17x1[] = { 0x00, 0x01, 0x02, 0x03, 0x04 };
 
-static const struct comedi_lrange range_pci1720 = {
+static const struct comedi_lrange pci1720_ao_range = {
        4, {
                UNI_RANGE(5),
                UNI_RANGE(10),
        }
 };
 
-static const struct comedi_lrange range_pci171x_da = {
+static const struct comedi_lrange pci171x_ao_range = {
        2, {
                UNI_RANGE(5),
                UNI_RANGE(10)
        int n_aichan;           /*  num of A/D chans */
        const struct comedi_lrange *rangelist_ai;       /*  rangelist for A/D */
        const char *rangecode_ai;       /*  range codes for programming */
-       const struct comedi_lrange *rangelist_ao;       /*  rangelist for D/A */
        unsigned int has_irq:1;
        unsigned int has_large_fifo:1;  /* 4K or 1K FIFO */
        unsigned int has_diff_ai:1;
                .n_aichan       = 16,
                .rangelist_ai   = &range_pci1710_3,
                .rangecode_ai   = range_codes_pci1710_3,
-               .rangelist_ao   = &range_pci171x_da,
                .has_irq        = 1,
                .has_large_fifo = 1,
                .has_diff_ai    = 1,
                .n_aichan       = 16,
                .rangelist_ai   = &range_pci1710hg,
                .rangecode_ai   = range_codes_pci1710hg,
-               .rangelist_ao   = &range_pci171x_da,
                .has_irq        = 1,
                .has_large_fifo = 1,
                .has_diff_ai    = 1,
                .n_aichan       = 16,
                .rangelist_ai   = &range_pci17x1,
                .rangecode_ai   = range_codes_pci17x1,
-               .rangelist_ao   = &range_pci171x_da,
                .has_irq        = 1,
                .has_ao         = 1,
                .has_di_do      = 1,
        [BOARD_PCI1720] = {
                .name           = "pci1720",
                .cardtype       = TYPE_PCI1720,
-               .rangelist_ao   = &range_pci1720,
                .has_ao         = 1,
        },
        [BOARD_PCI1731] = {
                s->type         = COMEDI_SUBD_AO;
                s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_COMMON;
                s->maxdata      = 0x0fff;
-               s->range_table  = board->rangelist_ao;
                switch (board->cardtype) {
                case TYPE_PCI1720:
                        s->n_chan       = 4;
+                       s->range_table  = &pci1720_ao_range;
                        s->insn_write   = pci1720_ao_insn_write;
                        break;
                default:
                        s->n_chan       = 2;
+                       s->range_table  = &pci171x_ao_range;
                        s->insn_write   = pci171x_ao_insn_write;
                        break;
                }