Chapter 2 Devices 2.2.9 Stepping Relays The function of the stepping relay: The stepping relay can be easily used in the industrial automation to set the procedure. It is the most basic device in the sequential function chart (SFC). Please refer to ISPSoft User Manual for more information related to sequential function charts. There are 2048 stepping relays, i.e. S0~S2047. Every stepping relay is like an output relay in that it has an output coil, contact A, and contact B. It can be used several times in the program, but it can not directly drive the external load. Besides, the stepping relay can be used as a general auxiliary relay when it is not used in the sequential function chart.
2.2.10 Timers 1. 100 millisecond timer: The timer specified by the instruction TMR takes 100 milliseconds as the timing unit. 2. 1 millisecond timer: The timer specified by the instruction TMRH takes 1 millisecond as the timing unit. 3. The timers for the subroutine’s exclusive use are T1920~T2047. 4. The accumulative timers are ST0~ST2047. If users want to use the device-monitoring function, they can monitor T0~T2047. 5. If the same timer is used repeatedly in the program, including in different instructions TMR and TMRH, the setting value is the one that the value of the timer matches first. 6.
If the same timer is used repeatedly in the program, it is OFF when one of the conditional contacts is OFF. 7. If the same timer is used repeatedly in the program as the timer for the subroutine’s exclusive use and the accumulative timer in the program, it is OFF when one of the conditional contacts is OFF. 8. When the timer is switched from ON to OFF and the conditional contact is ON, the timer is reset and counts again. 9. When the instruction TMR is executed, the specified timer coil is ON and the timer begins to count. As the value of the timer matches the setting value, the state of the contact is as follows. A.
The general-purpose timer When the instruction TMR is executed, the general-purpose timer begins to count. As the value of the timer matches the setting value, the output coil is ON. When Ч 0.0 is ON, the timer T0 takes 100 milliseconds as the timing unit and counts up. As the current value of the timer matches the setting value 100, the output coil of T0 is ON. When Ч 0.0 is OFF or there is a power cut, the current value of the timer is reset to 0 and the output coil is switched OFF. 2-51 Normally open (NO) contact ON Normally closed (NC) contact OFF