Wavetronix Click 500 (programmable controller) (CLK-500) - User Guide User Manual | Page 134 / 134 | Also for: Click 510 (communication tester) (CLK-510) - User Guide, Click 511 (digital I/O repeater) (CLK-511) - User Guide, Click 512 (vehicle alert) (CLK-512) - User Guide, Click 513 (traffic alert) (CLK-513) - User Guide, Click 514 (event logger) (CLK-514)