Product overview
1.1 S7-200 SMART CPU
S7-200 SMART
20
System Manual, V2.3, 07/2017, A5E03822230-AF
Table 1- 3
Standard expandable CPUs
Features
CPU SR20,
CPU ST20
CPU SR30,
CPU ST30
CPU SR40,
CPU ST40
CPU SR60,
CPU ST60
Dimensions: W x H x D (mm)
90 x 100 x 81
110 x 100 x 81
125 x 100 x 81
175 x 100 x 81
User memory
Program
12 Kbytes
18 Kbytes
24 Kbytes
30 Kbytes
User data
8 Kbytes
12 Kbytes
16 Kbytes
20 Kbytes
Retentive
10 Kbytes max.
1
10 Kbytes max.
1
10 Kbytes max.
1
10 Kbytes max.
1
On-board digital
I/O
•
Inputs
•
Outputs
•
12 DI
•
8 DQ
•
18 DI
•
12 DQ
•
24 DI
•
16 DQ
•
36 DI
•
24 DQ
Expansion modules
6 max.
6 max.
6 max.
6 max.
Signal board
1
1
1
1
High-speed
counters (6
total)
Single phase
4 at 200 kHz
2 at 30 kHz
5 at 200 kHz
1 at 30 kHz
4 at 200 kHz
2 at 30 kHz
4 at 200 kHz
2 at 30 kHz
A/B phase
2 at 100 kHz
2 at 20 kHz
3 at 100 kHz
1 at 20 kHz
2 at 100 kHz
2 at 20 kHz
2 at 100 kHz
2 at 20 kHz
Pulse outputs
2
2 at 100 kHz
3 at 100 kHz
3 at 100 kHz
3 at 100 kHz
PID loops
8
8
8
8
Real-time clock with 7-day back-up Yes
Yes
Yes
Yes
1
You can configure areas of V memory, M memory, C memory (current values), and portions of T memory (current val-
ues on retentive timers) to be retentive, up to the specified maximum amount.
2
The specified maximum pulse frequency is possible only for CPU models with transistor outputs. Pulse output operation
is not recommended for CPU models with relay outputs.
Refer to the technical specifications (Page 679) for the power requirements of the CPU and
the expansion modules. Use the worksheets in Appendix B, Calculating a power budget
(Page 790) to calculate your power budget.
