The 1785-L60L processor belongs to the trusted Allen-Bradley PLC-5 controller family. This programmable controller acts as the central hub for distributed I/O systems. It connects local, extended, and remote chassis through multiple communication interfaces. Therefore, it delivers exceptional flexibility for factory automation projects.
This controller features three built-in communication channels. Channel 1A and Channel 1B support remote I/O scanning, adapter mode, or DH+ peer-to-peer networking. Channel 2 functions as a dedicated extended-local I/O port for high-speed scanning. Additionally, the front panel includes a 25-pin RS-232 port (Channel 0) for ASCII and DF1 protocol communication.
The 1785-L60L provides 64,000 words of user memory with battery backup. This ensures program retention during power outages. For permanent storage, you can install an optional EEPROM module (such as the 1785-ME16, 1785-ME32, 1785-ME64, or 1785-M100) directly on the front panel. This makes program recovery quick and reliable.
The 1785-L60L controller supports a maximum total I/O count of 3072 points. This includes any combination of inputs and outputs. For complementary addressing, it can handle 3072 inputs plus 3072 outputs simultaneously. Analog I/O capacity also reaches 3072 channels, making it suitable for process control applications.
I/O scan times vary based on the link type. Extended-local racks scan in just 0.5 milliseconds per rack. Remote I/O scan times depend on baud rate: 10 ms at 57.6 kbit/s, 7 ms at 115.2 kbit/s, and 3 ms at 230.4 kbit/s. Consequently, you can optimize system speed based on your distance requirements.
This processor manages up to 81 I/O chassis in total. However, each remote I/O link supports a maximum of 32 chassis. Meanwhile, the extended-local link handles up to 16 chassis. This scalability allows the 1785-L60L to grow with your application needs.
The controller draws 3.3 Amps at 5 Volts from the backplane. This moderate power consumption ensures compatibility with standard PLC-5 power supplies. Furthermore, the unit includes a control coprocessor expansion port for additional processing capability.
Channel 1A and Channel 1B offer three distinct operating modes. In remote I/O scanner mode, the 1785-L60L supervises other controllers and I/O adapters on the link. It reads and writes I/O data between the master and remote devices seamlessly.
When configured as a remote I/O adapter, this controller manages its resident I/O while communicating with a supervisory controller. This mode is useful in distributed architectures where multiple controllers share a single remote I/O network.
Alternatively, you can set either channel as a DH+ port. DH+ enables peer-to-peer communication with other PLC-5 controllers or higher-level systems. Programming can also occur over the DH+ link, allowing multiple controllers to be programmed simultaneously. The maximum cable length for DH+ ranges from 3048 meters at 57.6 kbit/s to 762 meters at 230.4 kbit/s.
Channel 0 provides a 25-pin RS-232 interface with optical isolation. It supports ASCII, DF1 full-duplex, DF1 half-duplex master, and half-duplex slave protocols. This versatility makes it easy to connect to HMI panels, printers, or third-party devices.
The extended-local I/O link offers high-speed scanning for chassis located close to the controller. Using the 1771-ALX extended-local I/O adapter, you can connect up to 16 additional chassis within 100 feet of cable. Each rack scans in just 0.5 milliseconds, providing near-instantaneous I/O updates.
This parallel link delivers faster performance than standard remote I/O. For installations requiring longer distances, however, you should use the remote I/O link instead. The 1785-L60L automatically manages both link types, giving you installation flexibility.
The front panel features several LED indicators for quick diagnostics. The BATT LED shows battery status, alerting you when replacement is needed. The PROC indicator displays the current operating mode: green for RUN, red for fault conditions.
The FORCE indicator lights amber when I/O forces are enabled. This visual cue helps technicians avoid unintended operations during maintenance. Additionally, the COMM indicator monitors Channel 0 communication activity. Channel 1A, Channel 1B, and Channel 2 each have dedicated status LEDs for link integrity verification.
A three-position keyswitch allows mode selection: RUN, PROG, and REM. In RUN mode, outputs are enabled and programs execute normally. Program mode disables outputs, permitting file creation, modification, and deletion. Remote mode offers three sub-modes: Remote Run, Remote Program, and Remote Test. These sub-modes enable online editing and testing while maintaining operational safety.
The 1785-L60L operates reliably in industrial environments. It withstands temperatures from 0°C to 60°C and humidity levels from 5% to 95% (non-condensing). The unit is built for panel mounting and includes standard PLC-5 form factor dimensions. Its robust construction ensures long-term durability in harsh factory conditions.
Installing the 1785-L60L requires a compatible PLC-5 rack and power supply. First, verify that the backplane power capacity meets the 3.3 Amp requirement. Next, insert the processor into the appropriate slot, ensuring firm seating. Connect the required communication cables: RS-232, DH+ twinaxial cable, or remote I/O links.
Configure each communication channel according to your network topology. Use the programming software to set baud rates, node addresses, and protocol parameters. For extended-local links, keep cable lengths under 100 feet. For remote I/O, select the appropriate baud rate based on cable distance.
Finally, insert the EEPROM memory module if you plan to use it for program backup. The 1785-ME16, 1785-ME32, 1785-ME64, and 1785-M100 are all compatible options. After installation, perform a comprehensive test to verify I/O scanning and communication before placing the system into production.
Allen-Bradley 1785-L60L PLC-5/60L processor unit (1 piece)
Keyswitch (1 piece, installed)
Product documentation and quick-start guide (printed)
Anti-static packaging bag
Factory-sealed industrial carton
Q1: What memory modules are compatible with the 1785-L60L?
A: The 1785-L60L accepts EEPROM modules including the 1785-ME16, 1785-ME32, 1785-ME64, and 1785-M100. These provide non-volatile program backup directly on the processor.
Q2: How many I/O points can the 1785-L60L handle?
A: This controller supports up to 3072 total I/O points in any mix. Alternatively, it can handle 3072 inputs and 3072 outputs when using complementary addressing.
Q3: Can I program the 1785-L60L through the DH+ port?
A: Yes, DH+ communication supports programming alongside peer-to-peer networking. Multiple controllers on the same DH+ link can be programmed simultaneously from a single terminal.
Q4: What is the difference between extended-local and remote I/O links?
A: Extended-local I/O provides faster scan times (0.5 ms per rack) but limits cable length to 100 feet. Remote I/O supports longer distances (up to 3048 meters) with slower scan rates depending on baud rate.
Q5: How do I select the correct operating mode on the 1785-L60L?
A: Use the three-position keyswitch on the front panel. Turn it to RUN for normal operation, PROG for offline programming, or REM for remote access and online editing.
| Brand Name | |
| Model No. | 1785-L60L |
| Product Type | Standard Processor |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
