Product Summary
The Allen-Bradley 1785-L40B is a powerful Programmable Logic Controller from the trusted PLC-5 family. This controller features a robust 48KWords user memory. It supports up to 2048 total I/O points in any mix. You can also configure it for a complementary setup with 2048 inputs and 2048 outputs. This model handles medium to large automation applications with ease. It delivers reliable performance and flexible connectivity for demanding industrial environments.
Expert Technical Evaluation & Performance Review
The 1785-L40B controller operates with a standard processor module. It manages a maximum of 61 I/O chassis in total. This setup includes 1 local rack and 28 universal remote racks. The controller processes I/O scans at high speeds. Scan times reach just 3 ms per rack at 230.4 kbits/s. This speed ensures precise control in time-sensitive processes.
The system provides four embedded combination ports for DH+ or Remote I/O networks. You can configure each port as an adapter or a scanner. This design lets you implement four independent networks from one controller. The single serial port supports RS-232, RS-423, and RS-422A standards. This flexibility suits point-to-point communication over short distances.
Environmental tolerance is a key strength of this model. The controller operates reliably in temperatures from 0 to 60°C. It withstands non-operating conditions from -40 to 85°C. The unit draws 3.3A from the backplane and dissipates 17.3W of power. It requires a compatible 1771-P4S, -P6S, -P4S1, or -P6S1 power supply.
Memory expansion is simple with optional EEPROM backup cards. You can install the 1785-ME16 for 16K words. The 1785-ME32 and 1785-ME64 offer 32K and 64K words respectively. The 1785-ME100 provides 100K words of non-volatile storage. The controller uses a 1770-XYC battery to maintain battery-backed static RAM.
This controller handles up to 32 devices per I/O link. It supports a maximum of 2048 analog I/O points. The lack of protected memory means you must manage program access externally. The control coprocessor expansion port allows additional processing capabilities. These features make the 1785-L40B a versatile choice for complex automation systems.
Logistics & Standard Packaging Details
