PLC-5/20C Processor Overview

Cat. No. Processor User Memory Words, Max.  Memory Types Total I/O, Max. Analog I/O, Max. I/O Scan Time per Rack∆ 
ControlNet PLC-5 Processors
1785-L20C15 PLC-5/20C 16K •Battery-backed static RAM
•EEPROM program backup option using 1785-ME32, -ME64, and -M100
Forcible
•512 (any mix) or
•512 in + 512 out (complementary)
Non-forcible♦
•32000
Forcible
•512
Non-
forcible♦
•32000
ControlNet I/O
•0.5 ms (average)♠
Universal Remote I/O
•10 ms @ 57.6 kbit/s
•7 ms @ 115.2 kbit/s
•3 ms @ 230.4 kbit/s

 

The PLC-5® processors are single-slot modules that are placed into the left-most slot of a 1771 I/O chassis. They are available in a range of I/O, memory, and communication capability.

PLC-5 processors have ports configurable for either a Data Highway Plus messaging communication link or a Universal Remote I/O link. As a Universal Remote I/O port, it can be configured as either an I/O scanner port or an I/O adapter port. As an I/O scanner port, it monitors and controls the I/O on the link by communicating with the I/O adapters for those I/O. As an adapter port, it communicates only with the I/O scanner port on the link, passing a maximum of one I/O rack of input and output data between the two to provide distributed processing.

All PLC-5 processors have Data Highway Plus and RS-232-C/422-A/423-A communication ports. In addition to these ports, each Ethernet PLC-5 processor has an Ethernet communication port, and each ControlNet PLC-5 processor has a ControlNet communication port.

Although each Ethernet PLC-5 processor has on-board Ethernet ports; additional Ethernet ports can be added to any PLC-5 processor system with a 1785-ENET Ethernet Interface Module. PLC-5 processors do not have an on-board DeviceNet port. A DeviceNet port can be added to the system with a 1771-SDN scanner module.

Benefits

  1. Ladder-logic and structured-text programming
  2. Advanced instruction set including file handling, sequencer, diagnostic, shift register, immediate I/O, and program control instructions
  3. Multiple main control programs for segregation of control tasks
  4. Processor input interrupts and global status flags
  5. Programmable fault response for reacting to a fault before the system goes down
  6. Timed interrupt routine for examining specific information at specific time intervals
  7. Protected memory selectable by word on selected processors
  8. 512 through 3072 maximum forcible I/O in any mix
  9. Up to 50,176 maximum non-forcible I/O
  10. Processor-resident local I/O (1771 I/O modules)
  11. Extended-local I/O on selected processors (1771 I/O modules)
  12. Universal Remote I/O (1746, 1771, and 1794 I/O modules and 1791 I/O blocks)
  13. DeviceNet I/O (1794 I/O modules, 1792D I/O blocks)
  14. ControlNet I/O on selected processors (1771, 1734, 1794, 1797 I/O modules)
  15. Universal Remote I/O ports can be configured as either an I/O scanner port or an I/O adapter port

Built-in Web Services

Ethernet PLC-5 processors (1785-L20E, -L40E, and -L80E), and the Ethernet interface module (1785-ENET) provide built-in web capabilities:

  1. Web Diagnostics and Module Information lets a standard web browser access information stored in the PLC-5 processor data table, including module diagnostic information (requires RSLogix5, version 5.2 or later).
  2. Web User Provided Pages allows for unique Web page creation to provide custom data table information. Any Internet user who has network access to the PLC-5 processor can view these pages, which can be either HTML pages that contain data table elements, text and images, or Custom Data Monitor pages that contain data table elements in table form.
  3. Domain Name Service (DNS) lets Internet users access the built-in Web server by a specified name instead of by IP address (requires RSLogix5, version 5.2 or later).

PLC-5 Processors with Protected Memory (1785-L26B, -L46B, L86B, -L46C15)

All enhanced PLC-5 processors have memory protection. However, those processors designated as having the memory protection feature have the added capability of limiting access to individual words.

Choose a PLC-5 processor with protected memory when access must be limited to critical or proprietary areas of programs, selectively guard processor memory and I/O words, or restrict use of processor operations.

The PLC-5 protected memory feature expands system validity and security beyond what is provided by the password-and-privilege capability of the other PLC-5 enhanced processors. Custom software protection schemes can be designed for each application.

Rockwell Software programming software can be used to assign class privileges to specific user accounts or a user job function, such as system administrator, plant engineer, maintenance engineer, or operator. Using four privilege classes and associated passwords, access can be limited to critical program areas and restrict access to:

  1. Communication channels
  2. Remote nodes attached to a DH+ or ControlNet network
  3. Program files
  4. Data files
  5. Individual data words

The PLC-5/26, PLC-5/46, and PLC-5/86 protected processors are equivalent to the PLC-5/20, PLC-5/40, and PLC-5/80 standard processors, respectively, plus the added memory protection feature. These processors are listed under the heading “Standard PLC-5 Processors with Protected Memories” in the PLC-5 Processor selection tables.

The PLC-5/46C15 protected processor is equivalent to the PLC-5/40C15 ControlNet processor plus the added memory protection feature. This processor is listed under the heading “ControlNet PLC-5 Processors with Protected Memories” in the PLC-5 Processor selection tables.

Specifications

Time-of-Day Clock/Calendar
Maximum Variations at 60 °C ± 5 min per month
Typical Variations at 20 °C ± 20s per month
Timing Accuracy 1 program scan
Battery 1770-XYC
Operating Shock 30 g peak acceleration for 11 ±1 ms duration
Nonoperating Shock 50 g peak acceleration for 11 ±1 ms duration
Vibration 1 g at 10…500 Hz
0.012 in. peak-to-peak displacement
Operating Temperature 0…60 °C (32…140 °F)
Nonoperating Temperature -40…85 °C (-40…185 °F)
Relative Humidity 5…95% noncondensing
Certifications⋆ UL, CSA Class I Div 2 Hazardous, CE, C-Tick, EEx, EtherNet/IPODVA
⋆ When product is marked. See the Product Certification link at http://www.ab.com for Declarations of Conformity, Certificates, and other certification details.

Selecting the Processor Category

Three categories of PLC-5 processor are available:

  1. Standard — Standard PLC-5 processors feature versatile built-in communication options that permit development of a control architecture that is specific to an application, and an advanced programming instruction set.
  2. Ethernet — Ethernet PLC-5 processors offer embedded TCP/IP communication capabilities that let them communicate with other Ethernet PLC-5 processors and host computers. They thus integrate Allen-Bradley architecture into the industry standard TCP/IP network, offering high-performance peer-to-peer communication via use of PLC-5 message instructions. Ethernet PLC-5 processors are optimized for real-time sequential and regulatory control.
  3. ControlNet — ControlNet PLC-5 processors are used for control and information processing. They offer high-speed communication through a ControlNet port. The ControlNet network provides both I/O control faster than the Universal Remote I/O link and peer-to-peer communication faster than the DH+ network. These processors eliminate the need for block transfer programming when communicating with 1771 I/O modules on the ControlNet network that require a one-time configuration and then continuously read or write.

PLC-5 Processor Categories

Processor Category I/O, Max. I/O Chassis, Max. I/O Communication User Memory, Max. General
Communication Ports
Standard PLC-5 Processor 512 to 3072
(any mix)⋆
5 to 93⋆ •Processor-resident local I/O
•Extended local I/O
•Universal Remote I/O
•DeviceNet I/O‡
•8K to 100K words
•protected (PLC-5/26, -5/46, and -5/86 only)
•Ethernet§
•DH+
•RS-232-C/422-A/423-A
Ethernet
PLC-5 Processor
512 to 3072
(any mix)⋆
13 to 65⋆ •Processor-resident local I/O
•Universal Remote I/O
•DeviceNet I/O‡
•16K to 100K words •Ethernet
•DH+
•RS-232-C/422-A/423-A
ControlNet PLC-5 Processor Forcible
•512 to 3072 (any mix)⋆
Non-forcible
•3200 to 50176
77 to 125⋆ •Processor-resident local I/O
•Universal Remote I/O
•DeviceNet I/O‡
•ControlNet I/O
•6K to 100K words
•protected (PLC-5/46C only)
•Ethernet§
•ControlNet
•DH+
•RS-232-C/422-A/423-A
 
⋆ This does not include DeviceNet I/O.
‡ This type of I/O in this type of controller system requires a separate I/O scanner installed in an I/O module slot.
§ These are not on-board ports. They are available only through an interface installed in I/O module slot 0.

PLC-5 Processors

Standard PLC-5 Processors

  1. Total I/O, Max. is the actual I/O circuits, regardless of the number of connection points or I/O image bits. The number of I/O image bits (8, 16, or 32) that correspond to an I/O module limit the number of I/O at that module; however, some modules may have less I/O than I/O image bits. This includes local I/O, extended local I/O, and Universal Remote I/O combined. This does not include DeviceNet I/O.
    Any mix means that any number of the I/O can be inputs and any number can be outputs, with no placement restrictions.
    Complementary means that to configure this many I/O, pairs of modules must have duplicate addresses. This pair must be either 2 output modules sharing the same output image bits or an input module and an output module complementing each other. In either case, module placement must conform to these restrictions.
  2. I/O rack is an I/O addressing unit that can contain a max. of 128 I/O with unique addressing of I/O modules or 256 I/O with duplicate addressing of I/O modules.

 

Cat. No. Processor User Memory Words, Max.  Memory Types Total I/O, Max. Analog I/O, Max. I/O Scan Time per Rack∆ 
Standard PLC-5 Processors
1785-L11B PLC-5/11 8K •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•512 (any mix) or
•384 in + 384 out (complementary)
512 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L20B PLC-5/20 16 kB •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•512 (any mix) or
•512 in + 512 out (complementary)
512 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L30B PLC-5/30 32K •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•1024 (any mix) or
•1024 in and 1024 out (complementary)
1024 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L40B PLC-5/40 48 kB‡ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•2048 (any mix) or
•2048 in + 2048 out (complementary)
2048 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L40L PLC-5/40L 48K‡ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•2048 (any mix) or
•2048 in + 2048 out (complementary)
2048 •0.5 ms (ext. local)
•10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L60B PLC-5/60 64 kB§ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•3072 (any mix) or
•3072 in + 3072 out (complementary)
3072 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L60L PLC-5/60L 64 kB§ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•3072 (any mix) or
•3072 in + 3072 out (complementary)
3072 •0.5 ms (ext. local)
•10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L80B PLC-5/80 100 kB♣ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•3072 (any mix) or
•3072 in + 3072 out (complementary)
3072 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
Standard PLC-5 Processors with Protected Memories
1785-L26B PLC-5/26 16 kB •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•Protected
•512 (any mix) or
•512 in + 512 out (complementary)
512 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L46B PLC-5/46 48K‡ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•Protected
•2048 (any mix) or
•2048 in + 2048 out (complementary)
2048 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L86B PLC-5/86 100 kB♣ •Battery-backed static RAM
•EEPROM program backup option using:
1785-ME16, -ME32, -ME64, and -M100
•Protected
•3072 (any mix) or
•3072 in + 3072 out (complementary)
3072 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
 
⋆ Max. number of data table words and max. number of timers and counters are user-configured.
‡ Limit of 32K words per data table file.
§ Limit of 32K words per data table file and 56K words per program file.
♣ Limit of 32K words per data table file and a total data table size of 64K words. Limit of 56K words per program file.
∆ In a single chassis, extended-local or remote. For Universal Remote I/O unless otherwise specified.

Standard PLC-5 Processors (continued)

Cat. No. Processor Universal Remote / Extended Local-I/O / DH+ Ports (Mode) Number of I/O Chassis, Max. RS-232-C / 422-A / 423-A Ports‡  Backplane Current Load @ 5V
Total Extended Local Universal Remote 
Standard PLC-5 Processors
1785-L11B PLC-5/11 1 DH+/Remote I/O (Adap or Scan) 5 0 4 1 2.3 A
1785-L20B PLC-5/20 1 DH+
1 DH+/Remote I/O (Adap or Scan)
13 0 12 2.3 A
1785-L30B PLC-5/30 2 DH+/Remote I/O (Adap or Scan) 29 0 28 2.3 A
1785-L40B PLC-5/40 4 DH+/Remote I/O (Adap or Scan) 61 0 32 max. per I/O link 3.3 A
1785-L40L PLC-5/40L 2 DH+/Remote I/O (Adap or Scan)
1 Extended Local I/O
61 16 32 max. per I/O link 3.3 A
1785-L60B PLC-5/60 4 DH+/Remote I/O (Adap or Scan) 93 0 32 max. per I/O link 3.3 A
1785-L60L PLC-5/60L 2 DH+/Remote I/O (Adap or Scan)
1 Extended Local I/O
81 16 32 max. per I/O link 3.3 A
1785-L80B PLC-5/80 4 DH+/Remote I/O (Adap or Scan) 93 0 32 max. per I/O link 3.3 A
Standard PLC-5 Processors with Protected Memories
1785-L26B PLC-5/26 1 DH+
1 DH+/Remote I/O (Adap or Scan)
13 0 12 1 2.3 A
1785-L46B PLC-5/46 4 DH+/Remote I/O (Adap or Scan) 61 0 32 max. per I/O link 3.3 A
1785-L86B PLC-5/86 4 DH+/Remote I/O (Adap or Scan) 93 0 32 max. per I/O link 3.3 A
 
⋆ Universal Remote I/O Chassis — any device with a remote I/O adapter port compatible with the Allen-Bradley Universal Remote I/O link. This includes 1771 I/O chassis, 1791 I/O blocks, PanelView displays, RediPANEL displays, Dataliner displays, 1336 drives.
‡ RS-422-A and RS-423-A both have a cable length limitation of 61 m (200 ft).

Ethernet and ControlNet PLC-5 Processors

  1. Total I/O, Max. is the actual I/O circuits, regardless of the number of connection points or I/O image bits. The number of I/O image bits (8, 16, or 32) that correspond to an I/O module limit the number of I/O at that module; however, some modules may have less I/O than I/O image bits. This includes local I/O, ControlNet I/O, and Universal Remote I/O combined. This does not include DeviceNet I/O.
    Any mix means that any number of the I/O can be inputs and any number can be outputs, with no placement restrictions.
    Complementary means that to configure this many I/O, pairs of modules must have duplicate addresses. This pair must be either 2 output modules sharing the same output image bits or an input module and an output module complementing each other. In either case, module placement must conform to these restrictions.
  2. I/O rack is an I/O addressing unit that can contain a max. of 128 I/O with unique addressing of I/O modules or 256 I/O with duplicate addressing of I/O modules.

 

Cat. No. Processor User Memory Words, Max.  Memory Types Total I/O, Max. Analog I/O, Max. I/O Scan Time per Rack∆ 
Ethernet PLC-5 Processors
1785-L20E PLC-5/20E 16K •Battery-backed static RAM
•EEPROM program backup option using 1785-ME16, -ME32, and -ME64
•512 (any mix) or
•512 in + 512 out (complementary)
512 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L40E PLC-5/40E 48K‡ •Battery-backed static RAM
•EEPROM program backup option using 1785-ME16, -ME32, and -ME64
•2048 (any mix) or
•2048 in + 2048 out (complementary)
2048 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
1785-L80E PLC-5/80E 100K§ •Battery-backed static RAM
•EEPROM program backup option using 1785-ME16, -ME32, -ME64, -M100
•3072 (any mix) or
•3072 in + 3072 out (complementary)
3072 •10 ms at 57.6 kbit/s
•7 ms at 115.2 kbit/s
•3 ms at 230.4 kbit/s
ControlNet PLC-5 Processors
1785-L20C15 PLC-5/20C 16K •Battery-backed static RAM
•EEPROM program backup option using 1785-ME32, -ME64, and -M100
Forcible
•512 (any mix) or
•512 in + 512 out (complementary)
Non-forcible♦
•32000
Forcible
•512
Non-
forcible♦
•32000
ControlNet I/O
•0.5 ms (average)♠
Universal Remote I/O
•10 ms @ 57.6 kbit/s
•7 ms @ 115.2 kbit/s
•3 ms @ 230.4 kbit/s
1785-L40C15 PLC-5/40C 48K‡ •Battery-backed static RAM
•EEPROM program backup option using 1785-ME32, -ME64, and -M100
Forcible
•2048 (any mix) or
•2048 in + 2048 out (complementary)
Non-forcible♦
•48000
Forcible
•2048
Non-
forcible♦
•48000
ControlNet I/O
•0.5 ms (average)♠
Universal Remote I/O
•10 ms @ 57.6 kbit/s
•7 ms @ 115.2 kbit/s
•3 ms @ 230.4 kbit/s
1785-L80C15 PLC-5/80C 100K§ •Battery-backed static RAM
•EEPROM program backup option using 1785-ME32, -ME64, and -M100
Forcible
•3072 (any mix) or
•3072 in + 2048 out (complementary)
Non-forcible♦
•50176
Forcible
•3072
Non-
forcible♦
•50176
ControlNet I/O
•0.5 ms (average)♠
Universal Remote I/O
•10 ms @ 57.6 kbit/s
•7 ms @ 115.2 kbit/s
•3 ms @ 230.4 kbit/s
ControlNet PLC-5 Processors with Protected Memories
1785-L46C15 PLC-5/46C 48K‡ •Battery-backed static RAM
•EEPROM program backup option using 1785-ME32, -ME64, and -M100
•Protected
Forcible
•2048 (any mix) or
•2048 in + 2048 out (complementary)
Non-forcible♦
•48000
Forcible
•2048
Non-
forcible♦
•48000
ControlNet I/O
•0.5 ms (average)♠
Universal Remote I/O
•10 ms @ 57.6 kbit/s
•7 ms @ 115.2 kbit/s
•3 ms @ 230.4 kbit/s
 
⋆ Max. number of data table words and max. number of timers and counters are user-configured.
‡ Limit of 32K words per data table file.
§ Limit of 32K words per data table file and a total data table size of 64K words. Limit of 56K words per program file.
∆ In a single non-local chassis.
♦ Non forcible I/O is only available as ControlNet I/O.
♠ With several I/O chassis connected to the processor across a ControlNet link, the average I/O scan time per I/O rack in a single chassis is 0.5 ms. However the min. time for a complete ControlNet I/O scan (network update time) is 2 ms. Therefore, with a single I/O chassis connected to the processor across a ControlNet link, the min. I/O scan time for that single I/O chassis is 2 ms. Even with several I/O chassis connected to the processor across a ControlNet link, the min. time for an individual I/O chassis to be updated is 2 ms.

Ethernet and ControlNet PLC-5 Processors (continued)

Cat. No. Processor ControlNet / Ethernet / Remote / Extended Local-I/O / DH+ Ports (Mode) Number of I/O Chassis, Max. RS-232-C / 422-A / 423-A Ports  Backplane Current Load at 5V
Total  Extended Local Universal Remote‡ 
Ethernet PLC-5 Processors
1785-L20E PLC-5/20E •1 Ethernet
•1 DH+
•1 DH+/Remote I/O (Adap or Scan)
13 0 12 1 3.6 A
1785-L40E PLC-5/40E •1 Ethernet
•2 DH+/Remote I/O (Adap or Scan)
61 0 60 1 3.6 A
1785-L80E PLC-5/80E •1 Ethernet
•2 DH+/Remote I/O (Adap or Scan)
65 0 64 1 3.6 A
ControlNet PLC-5 Processors
1785-L20C15 PLC-5/20C •1 ControlNet (dual media)
•1 DH+
•1 DH+/Remote I/O (Adap or Scan)
77 0 12 1 2.7 A (typ)
3.0 A (max)
1785-L40C15 PLC-5/40C •1 ControlNet (dual media)
•2 DH+/Remote I/O (Adap or Scan)
125 0 60 1 3.0 A
1785-L80C15 PLC-5/80C •1 ControlNet (dual media)
•2 DH+/Remote I/O (Adap or Scan)
125 0 60 1 3.0 A
ControlNet PLC-5 Processor with Protected Memory
1785-L46C15 PLC-5/46C •1 ControlNet (dual media)
•2 DH+/Remote I/O (Adap or Scan)
125 0 60 1 3.0 A
 
⋆ Limited by data-table size and how much data table you use for each chassis.
‡ Universal Remote I/O Chassis — any device with a remote I/O adapter port compatible with the Allen-Bradley Universal Remote I/O link. This includes 1771 I/O chassis, 1791 I/O blocks, PanelView displays, RediPANEL displays, Dataliner displays, 1336 drives.
§ The ControlNet I/O map table can contain up to 128 entries. Each map-table entry corresponds to one scheduled transfer of data.
♣ RS-422-A and RS-423-A both have a cable length limitation of 61m (200 ft).

Memory Devices

Cat. No. Description For this Product Function Memory Size
1785-ME16 EEPROM Standard PLC-5 processors Program backup 16K words
1785-ME32 EEPROM Standard PLC-5 processors Program backup 32K words
1785-ME64 EEPROM Standard PLC-5 processors Program backup 64K words
1785-M100 EEPROM Standard PLC-5 processors Program backup 100K words
 

PLC-5 Processor Backup System

Benefits

  1. Easy to configure
  2. Needs no additional programming for most systems
  3. Applies state-of-the-art ControlNet services to enable synchronized scanning without the need for a dedicated connection
  4. Offers redundant media for increased network availability
  5. Performs equivalence checking of key structures and files to detect divergence automatically, without additional programming
  6. Provides user-configurable file transfers of application-specific data for increased system integrity
  7. Enables manual switch-over for ease of testing and troubleshooting
  8. Records switch-over activity with time-stamping for subsequent diagnostics

Hot-Backup Memory Cartridge

Cat. No. Compatible Processors Memory Size
1785-CHBM 1785-L40C15 or 1785-L80C15 100K words