What does the 17 in Catalog Number stands for ?

[EMHBH 0]

Hi, I'm wondering, what dose the 17 in in Allan Bradley catalog number stands for (17XX-XXXX) ? Thanks.

[Ken Roach 194]

Decades ago, Allen-Bradley had product data sheets called "Bulletins", so product families took on Bulletin numbers for their part numbers. Well known Bulletins include Bulletin 509 for motor starters, and Bulletin 800 for pushbuttons and Bulletin 802 for limit switches, or Bulletin 1492 for terminal blocks. PLC controllers also had Bulletin numbers. The PLC-5 was Bulletin 1785, and its I/O system was Bulletin 1771. Modern ControlLogix are Bulletin 1756, and CompactLogix are Bulletin 1978 and 1769. So the number doesn't really stand for anything. It's just a number that an Allen-Bradley manager chose in the 1980's to designate their new control devices.