Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 28)

Choosing Hardware
Chapter 2
2-9
Choose from the following PLC-5 processors.
Table 2.I
Classic PLCĆ5 Processor Selection ChartĊPart 1
Processor/
Cat. No.
Maximum User
Memory Words
EEPROM Module
Memory (Words) &
Module Number
Total I/O Maximum
(any mix)
Analog
I/O Max
Program Scan Time /
K Word
I/O Scan time/Rack
(in a single Chassis,
extĆlocal or remote)
Multiple
MCPs /
Quantity
PLCĆ5/10
(1785ĆLT4) 6 K 8 K (1785ĆMJ)
• 512 (32ĆI/O modules)
• 256 (16ĆI/O modules)
• 128 (8ĆI/O modules) 256
2 ms (discrete logic)
8 ms (typical) N/A No / 1
PLCĆ5/12
(1785ĆLT3) 6 K 8 K (1785ĆMJ)
• 512 (32ĆI/O modules)
• 256 (16ĆI/O modules)
• 128 (8ĆI/O modules) 256
2 ms (discrete logic)
8 ms (typical)
• 10 ms @ 57.6 kbps
(remote) No / 1
PLCĆ5/15
(1785ĆLT)
6 K expandable
to 10 K or 14 K 8 K (1785ĆMJ)
• 512 (any mix) or
• 512 in + 512 out
(complementary) 512
2 ms (discrete logic)
8 ms (typical)
• 10 ms @ 57.6 kbps
(remote) No / 1
PLCĆ5/25
(1785ĆLT2)
13 K
expandable to
17 K or 21 K
8 K (1785ĆMJ) or
16 K (1785ĆMK)
• 1024 (any mix) or
• 1024 in + 1024 out
(complementary) 1024
2 ms (discrete logic)
8 ms (typical)
• 10 ms @ 57.6 kbps
(remote) No / 1
Table 2.J
Classic PLCĆ5 Processor Selection ChartĊPart 2
Processor/ Number of Remote I/O Extended Local
Maximum
Number of
Maximum Number of I/O
Chassis
Number of
RSĆ232/
422/ 423
Remote I/O
Transmission
Backplane
Current Processor/
Cat. No.
Number of Remote I/O, ExtendedĆLocal
I/O, and DH+ Ports
Number of
I/O Racks Total Ext Local Remote
422/ 423
ports
Transmission
Rates 1
Current
Load
PLCĆ5/10
(1785ĆLT4) • 1 DH+ 1 1 0 0 0 ĆĆ 2.5A
PLCĆ5/12
(1785ĆLT3)
• 1 DH+
• 1 Remote I/O (Adapter Only) 4 1 0 0 0 57.6 kbps 2.5A
PLCĆ5/15
(1785ĆLT)
• 1 DH+
• 1 Remote I/O (Adapter or Scanner) 4 13 0 12 0 57.6 kbps 2.5A
PLCĆ5/25
(1785ĆLT2)
• 1 DH+
• 1 Remote I/O (Adapter or Scanner) 8 17 0 16 0 57.6 kbps 2.5A
Use the following steps as guidelines for selecting a power supply for a
chassis that contains a PLC-5 processor, a 1771-AS or -ASB remote I/O
adapter module, or a 1771-ALX extended-local I/O adapter module.
1. Determine the input voltage for the power supply.
2. Calculate the total backplane current draw for I/O modules by
adding together the backplane current draw for each I/O module in
that chassis.
Choosing a Classic PLCĆ5
Processor for Your
Application
Selecting Power Supplies
1771ĆP7