梯形图常用指令

字符串处理指令

字符串比较（见前述比较指令部分：等于EQU、不等于NEQ、大于GRT、大于等于GEQ、小于LES、小于等于LEQ、表达式比较CMP）

STOD - String to DINT conversion (ACI)

DTOS - DINT to String conversion (AIC)

STOR - String to Real conversion

RTOS - Real to String conversion

CONCAT - String concatenate (ACN)

MID - String middle extract (AEX)

FIND - String search (ASC)

DELETE - String delete

INSERT - String Insert

LEFT、RIGHT、MID、LOWER、UPPER、REPEAT

ASCII串口操作指令

ACL – ASCII Clear Receive and/or Send Buffer

ACB – ASCII Number of characters in buffer

ABL – ASCII Test for Buffer Line

AHL – ASCII Handshake Line

ARD – ASCII Read

ARL – ASCII Read Line

AWA – ASCII Write with append

AWT – ASCII Write

此外还有超过30条专用伺服控制指令