Wavetronix Click 500 (programmable controller) (CLK-500) - Developer Guide User Manual | 196 pages | Also for: Click 510 (communication tester) (CLK-510) - Developer Guide, Click 511 (digital I/O repeater) (CLK-511) - Developer Guide, Click 512 (vehicle alert) (CLK-512) - Developer Guide, Click 513 (traffic alert) (CLK-513) - Developer Guide, Click 514 (event logger) (CLK-514)