From West Wide Systems:
Entertainment lighting equipment uses a control system called DMX512. DMXCalc is a simple and elegant calculator which does address arithmetic for DMX equipment. You can enter a DMX universe number and a device address to have DMXCalc calculate the absolute address. Or enter an absolute address to see the universe and device address. The + and - buttons can be set to increment or decrement the address by any block size. Handy for addressing a sequence of moving lights. When there is not enough space in the current universe for another fixture, the Address and + values turn red. Some DMX equipment utilizes dip switches to configure the address. The dip switch page has switches which show the settings for the current address value, or you can set the switches to match those on a light and discover what its address is. The sound button "plays" dipswitch settings so you can set switches without looking at the display. The new Block page can be loaded with a range of blocks, based on the block size and starting at the current address. Tapping any block on the list loads that address into the calculator and dip switches, and tapping the arrow shows a list of all locations in the block, with both local and absolute addresses. This feature is particularly useful for addressing a series of moving lights, dimmer packs, or LED fixtures. A fourth page has a quick reference list showing all DMX level values from 0 to 255, with corresponding percentage, hexadecimal, and MIDI values. Altogether indispensable for the entertainment lighting technician.