In the beginning, only a few of the 35 mm guns had a limited remote control function, most of these guns were manually controlled. Then, full-scale remote operation and automatic tracking function were included in the guns mounted on the PLH "Shikishima" introduced in 1989. In addition, the 20 mm gun systems were added to the standard equipment list as JM61-RFS, and they have been mounted on many patrol vessels. And in order to counter the heavily armed North Korean naval trawlers in the event of an engagement, most recently PLs have been equipped with a 40 mm L/70 gun or 30 mm chain gun remotely controlled with an optical director.