User manual

Choosing Hardware
Chapter 2
2-9
Choose from the following PLC-5 processors.
Table 2.I
Classic
PLC5 Processor Selection ChartPart 1
Processor/
Cat.
No.
Maximum User
Memory Words
EEPROM Module
Memory (W ords) &
Module Number
Total I/O Maximum
(any mix)
Analog
I/O Max
Program Scan T ime /
K W ord
I/O Scan time/Rack
(in a single Chassis,
extlocal or remote)
Multiple
MCPs /
Quantity
PLC5/10
(1785LT4)
6 K 8 K (1785MJ)
• 512 (32I/O modules)
• 256 (16I/O modules)
• 128 (8I/O modules)
256
2 ms (discrete logic)
8 ms (typical)
N/A No / 1
PLC5/12
(1785LT3)
6 K 8 K (1785MJ)
• 512 (32I/O modules)
• 256 (16I/O modules)
• 128 (8I/O modules)
256
2 ms (discrete logic)
8 ms (typical)
• 10 ms @ 57.6 kbps
(remote)
No / 1
PLC5/15
(1785LT)
6 K expandable
to 10 K or 14 K
8 K (1785MJ)
• 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
PLC5/25
(1785LT2)
13 K
expandable to
17 K or 21 K
8 K (1785MJ) or
16 K (1785MK)
• 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
PLC5 Processor Selection ChartPart 2
Processor/
Number of Remote I/O Extended Local
Maximum
Number of
Maximum Number of I/O
Chassis
Number of
RS232/
422/ 423
Remote I/O
Transmission
Backplane
Current
Processor/
Cat. No.
Number of Remote I/O, ExtendedLocal
I/O, and DH+ Ports
Number of
I/O Racks
Total Ext Local Remote
422/ 423
ports
Transmission
Rates
1
Current
Load
PLC5/10
(1785LT4)
• 1 DH+
1 1 0 0 0  2.5A
PLC5/12
(1785LT3)
• 1 DH+
• 1 Remote I/O (Adapter Only)
4 1 0 0 0
57.6 kbps
2.5A
PLC5/15
(1785LT)
•1 DH+
• 1 Remote I/O (Adapter or Scanner)
4 13 0 12 0
57.6 kbps
2.5A
PLC5/25
(1785LT2)
•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 PLC5
Processor for Your
Application
Selecting Power Supplies
1771P7