The PLC-5® processor module in a 1771 platform provides a proven approach for industrial control. PLC-5 processors are high-speed, single-slot processors used for control and information processing. They are designed for larger sequential and regulatory control applications with specialized I/O requirements and/or the need to coordinate with other processors and devices.
- Plc 5 1/2 Slot Addressing Machine
- Plc 5 1/2 Slot Addressing Tool
- Plc 5 1/2 Slot Addressing Machines
- Plc 5 1/2 Slot Addressing System
PLC-5 processors are available in a range of I/O capacity and memory size, and can be connected in a variety of networks for distributed processing and distributed I/O. The 1771 I/O products offer a full range of digital and analog I/O (including intelligent I/O) in a rugged modular assembly.
. The SLC-500 I/O channels are numbered in decimal (versus octal for the PLC-5). The SLC-500 has no slots numbered zero. The SLC-500 instruction set is very close to the original PLC-5 processors. In general, the SLC-500 programming software has a few less features than the PLC-5 programming software. When PLC rack is inserted in PLC manager, slots startwith number 1. If I use Allen-Bradley PLSs, the module numbers start with 0. So all the addressing. Note: Discrete I/O is Not Supported by SLC 5/01 and 5/02. There are a few different formats of addressing that C-more supports when connecting to the Allen-Bradley SLC 500 and MicroLogix PLCs. The Expanded I/O format allows the slot and word to be specified, which is more typical when trying to access Analog I/O data.
Benefits
- Modularity — Modular I/O and communication interfaces provide a configurable and expandable system. A system should be configured for the required number of I/O and the communication networks. Later, when system expansion is necessary, I/O or communication interfaces can be added.
- Speed — Fast delivery of messages between networks, between links within networks, and between modules across the backplane.
SIMATIC S5 S5-115U Programmable Controller Manual CPU 941-7UB11 CPU 942-7UB11 CPU 943-7UB11 and CPU 943-7UB21 CPU 944-7UB11 and CPU 944-7UB21 EWA 4NEB 811 6130-02b.
Plc 5 1/2 Slot Addressing Machine
- Toughness — Industrially-hardened hardware platform is designed to withstand the vibrations, thermal extremes, and electrical noise associated with harsh industrial environments.
- Broad I/O options — A large selection of 1771 I/O modules available for use in the local I/O chassis, and an even larger selection of I/O available at locations remote from the processor, can be connected across ControlNet™, DeviceNet™, and Remote I/O links.
Communication
A PLC-5 processor communicates across the 1771 backplane to 1771 I/O modules in the chassis in which the processor resides. The different models of PLC-5 processors have various on-board ports for communication with other processors, computers, and remotely located I/O. Also, separate modules are available to provide additional communication ports.
Each PLC-5 processor has a built-in RS-232/422/423 communication port. Each PLC-5 processor also has one or more on-board ports that can be configured for either Data Highway Plus (DH+) or Universal Remote I/O. As a Universal Remote I/O port, it can be configured as either an I/O scanner port or an I/O adapter port. Selected models of PLC-5 processors have on-board ports for Ethernet, ControlNet, or Extended Local I/O communication.
In addition to the on-board ports available with PLC-5 processors, adding another communication port for a PLC-5 processor is as simple as adding an optional communication module.
I/O adapter modules for 1771 I/O are available for ControlNet, Universal Remote I/O, and Extended Local I/O links. An I/O adapter module in a chassis with I/O modules interfaces the I/O modules with the I/O link for communication with a scanner port of a processor at another location.
System Components
A PLC-5 / 1771 control system at minimum consists of a processor module and I/O modules in a single 1771 chassis with a power supply. Choose the processor module with the on-board communication ports needed.
On-board Universal Remote I/O scanner ports are available on all PLC-5 processors. On-board Extended Local I/O scanner ports are available on some PLC-5 processors. On-board ControlNet ports are available on some PLC-5 processors. To provide a DeviceNet I/O scanner port to the system, a DeviceNet scanner module (1771-SDN) is necessary.
Typical Configurations
In this typical configuration, a ControlNet port on the processor module interfaces the processor to the ControlNet link. In each of the two chassis remote from the processor, a 1771-ACN15 I/O adapter module provides I/O modules in those chassis with an interface to the ControlNet link. The PLC-5 processor monitors/controls the I/O in its local I/O chassis as well as the I/O in the remote locations.
The 1771 power supply module plugs into an I/O module slot, or you can connect a stand-alone 1771 power supply to the left end of each chassis.
PLC-5 Processors Overview
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
- Ladder-logic and structured-text programming
- Advanced instruction set including file handling, sequencer, diagnostic, shift register, immediate I/O, and program control instructions
- Multiple main control programs for segregation of control tasks
- Processor input interrupts and global status flags
- Programmable fault response for reacting to a fault before the system goes down
- Timed interrupt routine for examining specific information at specific time intervals
- Protected memory selectable by word on selected processors
- 512 through 3072 maximum forcible I/O in any mix
- Up to 50,176 maximum non-forcible I/O
- Processor-resident local I/O (1771 I/O modules)
- Extended-local I/O on selected processors (1771 I/O modules)
- Universal Remote I/O (1746, 1771, and 1794 I/O modules and 1791 I/O blocks)
- DeviceNet I/O (1794 I/O modules, 1792D I/O blocks)
- ControlNet I/O on selected processors (1771, 1734, 1794, 1797 I/O modules)
- 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:
- 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).
- 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.
- 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:
- Communication channels
- Remote nodes attached to a DH+ or ControlNet network
- Program files
- Data files
- 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.
Introduction to the PLC-5 Chassis
The PLC-5 Chassis is the device which holds modules. In the PLC-5 system, we will first configure several switches for the desired operation. In this post, we’ll walk through each switch setting for both a PLC-5 Processor, and a 1771-ASB. Another key point is that the chassis comes in 4 sizes: 4-slot, 8-slot, 12-slot, and 16-slot. Shown Below is a 4-Slot chassis. Notice the slot for the processor does not count as an I/O Slot.
The first thing to remember is that the chassis is not called a “rack” in the PLC-5. The chassis holds modules, whereas a rack is a memory location in the processor.
Plc 5 1/2 Slot Addressing Tool
DIP switches
On the backplane, you see 8 Dip Switches. These switches configure the chassis for the desired operation.
In this case, we have 8 “Rocker” Switches. If we press a switch in on the left, the switch is off. In like manner, if we press a switch in on the right, it’s on. It’s important to remember to not use a pencil point when setting these switches. The graphite could cause the switch to be permanently on.
For a PROCESSOR in this chassis:
Plc 5 1/2 Slot Addressing Machines
Switch 1: Last State — If this switch is ON, the outputs of the chassis will stay in their last state if a hardware failure occurs. Otherwise, they are shut off.
Switch 2 and 3: Always Off — If a processor resides in this chassis, we do not use these two switches. However, these switches could be used if an adapter or PLC-2 processor was in this slot.
Switch 4 and 5: Addressing Mode — The addressing mode tells the processor how many slots equal a group of memory. (A group 16 bits of input and 16 bits of output). If both switches are OFF, every 2 slots equal a group (2-slot addressing). With 4 off and 5 on, every slot equals a group (1-slot addressing). When 4 is on and 5 is off, every 1/2 slot equals a group. (1/2 slot addressing) — Both switches ON is an invalid setting.
Switch 6 and 7: EEPROM Transfer — If you use an EEPROM as an onboard backup of your project, we will need to decide the conditions in which we need the EEPROM to load. With 6 and 7 off, the EEPROM will load at power-up. With both switch 6 and 7 on, the EEPROM will load only if the processor memory is invalid. If there is no EEPROM, or we wish to load the EEPROM manually, turn 6 on and 7 off.
Switch 8: Memory Protect — Turn this switch ON to enable memory protection. This will prevent a user from downloading to the processor, or performing an online edit. Normally, we’ll leave this switch OFF, and memory protection is disabled. This allows us to make changes to the project as we need.
For an ADAPTER in the chassis:
Realize that these settings are different than for a processor. You must take important care to use the correct chart for the settings of your chassis.
Switch 1: Last State — This is for the last state of the outputs if a communication fault occurs. In this situation, leave switch 1 off. The outputs will be turned off if a communication loss is detected. This is usually the recommended setting. If you turn on Switch 1, the outputs will remain in the last state if a communication loss occurs.
Plc 5 1/2 Slot Addressing System
Switch 2: Processor Restart Lockout — If this switch is off, the processor will not restart the chassis if a communication loss occurs. You must physically reset the chassis with a reset button on the adapter, or cycle power. When this switch is on, the processor can restart the chassis when communication is restored.
Switch 3 and 4: Always Off — These switches are not used for an Adapter in the chassis. These switches are used for other purposes.
Switch 5 and 6: Addressing Mode — For 2 slot addressing, shut off both switches. Turn switch 5 on, and 6 off, to select 1 slot addressing. Set 5 off, and 6 on for 1/2 slot addressing. Both switches on is an invalid setting.
Switch 7 and 8: Always off — Again, we do not use these if an adapter is in the chassis.
Power Supply Jumper
It’s important to remember the power supply jumper. When you use a slot mounted power supply, such as the 1771-P4S, the jumper is in the Y position. However, if you use an external power supply, such as the 1771-P7, set the jumper to the “NO” position.
To verify the accuracy of this information before implementing it in any way, consult the PLC-5 Quick Reference Guide. this is an invaluable tool to have when setting up a chassis!
For other information on the PLC-5, visit the PLC-5 Category Page!
— Ricky Bryce