Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 40)

2 Functions of Devices in DVP-PLC
DVP-PLC Application Manual
2-12
EH/EH2/SV series MPU:
Initial
S0 ~ S9, 10 points. Can be modified to be latched by setting up
parameters.
Zero return
S10 ~ S19, 10 points, used with IST instruction. Can be modified to be
latched by setting up parameters.
General purpose
S20 ~ S499, 480 points. Can be modified to be latched by setting up
parameters.
Latched
S500 ~ S899, 400 points. Can be modified to be non-latched by setting
up parameters.
Step relay S
Alarm
S900 ~ S1023, 124 points. Can be modified to be latched by setting up
parameters.
Total
1,024 points
Functions of step relays:
The step relay S can easily set up the procedure in the industrial automation, which is the most basic device in
the the sequential function chart (SFC) and has to be used with STL, RET instructions.
The device No. of S is S0 ~ S1023 (total 1,024 points) and both step relay S and output relay Y have output coils
and contact A, B, and there is no limitation on the times of using the contact. S cannot directly drive the external load.
When the step relay is not used in SFC, it can be used as a normal auxiliary relay. There are four types of step relays:
1. Initial step relay: S0 ~ S9, total 10 points, used for initial steps.
2. Zero return step relay: S10 ~ S19, total 10 points. S10 ~ S19 are planned for zero return when used with API 60
IST instruction in the program. If they are not used with IST, they will become normal step relays.
3. General purpose step relay: S20 ~ S511, total 492 points (for SA/SX/SC series MPU); S20 ~ S499, total 480
points (for EH/EH2/SV series MPU). Used for general purposes in SFC and their status will all be cleared when
the operation of the PLC encounters power cut.
4. Latched step relay: S512 ~ S895, total 384 points (for SA/SX/SC series MPU); S20 ~ S127, total 108 points (for
ES/EX/SS series MPU); S500 ~ S899, total 400 points (for EH/EH2/SV series MPU). Used for latched function in
SFC and their status will all be retained when the operation of the PLC encounters power cut. They will remain at
the status before the power cut when the PLC is powered again.
5. Alarm step relay: S896 ~ S1023, total 128 points (for SA/SX/SC series MPU); S900 ~ S1023, total 124 points
(for EH/EH2/SV series MPU). Used with alarm driving instruction API 46 ANS as an alarm contact for recording
the alarm messages or eliminating external malfunctions.
2.6 Numbering and Functions of Timers [T]
No. of timers (in decimal)
ES/EX/SS series MPU:
100ms general purpose T0 ~ T63, 64 points
10ms general purpose T64 ~ T126, 63 points (M1028 = On:10ms; M1028 = Off:100ms)
Timer T
1ms general purpose T127, 1 point
Total
128 points