ISPSoft User Manual 7.3.2 Pulse Instructions for Function Blocks (AH/AS Series ONLY) Pulse instructions such as LDP, LDF, NP, and PN can not be used in the function blocks in a project for an AH/AS series CPU module, and therefore users can consider using the following instructions. Please refer to AH/AS Programming Manual for more information about the instructions. PED and NED PED and NED are similar to LDP and LDF in functions. PED and NED differ from LDP and LDF in that users have to specify Boolean devices. The Boolean devices that users specify when they use PED and NED in a project can not be used in other places in the project. Otherwise, an error will occur.
LDP (rising-edge detection) and LDF (falling-edge detection) can be used in a POU of the program type. Users can use PED in place of LDP in a function block, but they have to specify a device, e.g. M100 in the figure below. Users can use NED in place of LDF in a function block, but they have to specify a device, e.g. M200 in the figure below. FB_NP and FB_PN FB_NP and FB_PN are similar to NP and PN in functions. FB_NP and FB_PN differ from NP and PN in that users have to specify Boolean devices. The Boolean devices that users specify when they use NED and PED in a project can not be used in other places in the project. Otherwise, an error will occur.
NP can be used in a POU of the program type. 7-34