Communication Adapter Module | Allen-Bradley 1785-KA5
The Allen-Bradley 1785-KA5 is a specialized communication adapter module designed to bridge Data Highway Plus (DH+) networks with RS-485 Data Highway (DH-485) networks. It facilitates seamless data exchange, program uploads, and downloads between PLC-5 processors and SLC 500 controllers. This unit enables multi-network industrial architectures to share messaging instructions efficiently without requiring external protocol conversion hardware.
Operational Modes and Network Integration
The module operates in either gateway or router mode, depending on configuration switch settings. In gateway mode, DH+ devices initiate data transactions while connected SLC processors respond to read and write requests. Router mode supports flexible peer-to-peer messaging capabilities, allowing devices across both network topologies to interchange data packets reliably.
Configuration and Physical Setup
Configuration is handled through onboard DIP switch banks that establish station addresses and baud rates for each channel. The module supports a maximum DH-485 cable segment length of 1219 m using shielded twisted-pair media alongside compatible link couplers. Front-panel diagnostic LEDs provide real-time status indication for monitoring network health and troubleshooting communication faults.
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Model | 1785-KA5 |
| Product Type | Communication Adapter Module |
| Network Compatibility | Data Highway Plus (DH+) to DH-485 (RS-485) |
| Baud Rate (DH+) | 57.6 Kbps |
| Baud Rate (DH-485) | 300 bps to 19.2 Kbps |
| Maximum DH-485 Cable Length | 1219 m (4000 ft) |
| Backplane Power Requirement | 1.2 A at 5 VDC |
| Weight | 0.82 kg |
| Category | PLCs / Machine Control |
Frequently Asked Questions
Q: Can an SLC 500 processor initiate a message request to a PLC-5 device when the 1785-KA5 is set to gateway mode?
A: No. In gateway mode, DH+ devices must initiate all communication requests, while SLC processors on the DH-485 link function as responders only.
Q: What baud rates are supported on the DH-485 side of the network?
A: The DH-485 network channel supports selectable baud rates ranging from 300 bps up to 19.2 Kbps, configured via onboard DIP switches.
Communication Adapter Module | Allen-Bradley 1785-KA5
Communication Adapter Module | Allen-Bradley 1785-KA5
The Allen-Bradley 1785-KA5 is a specialized communication adapter module designed to bridge Data Highway Plus (DH+) networks with RS-485 Data Highway (DH-485) networks. It facilitates seamless data exchange, program uploads, and downloads between PLC-5 processors and SLC 500 controllers. This unit enables multi-network industrial architectures to share messaging instructions efficiently without requiring external protocol conversion hardware.
Operational Modes and Network Integration
The module operates in either gateway or router mode, depending on configuration switch settings. In gateway mode, DH+ devices initiate data transactions while connected SLC processors respond to read and write requests. Router mode supports flexible peer-to-peer messaging capabilities, allowing devices across both network topologies to interchange data packets reliably.
Configuration and Physical Setup
Configuration is handled through onboard DIP switch banks that establish station addresses and baud rates for each channel. The module supports a maximum DH-485 cable segment length of 1219 m using shielded twisted-pair media alongside compatible link couplers. Front-panel diagnostic LEDs provide real-time status indication for monitoring network health and troubleshooting communication faults.
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Model | 1785-KA5 |
| Product Type | Communication Adapter Module |
| Network Compatibility | Data Highway Plus (DH+) to DH-485 (RS-485) |
| Baud Rate (DH+) | 57.6 Kbps |
| Baud Rate (DH-485) | 300 bps to 19.2 Kbps |
| Maximum DH-485 Cable Length | 1219 m (4000 ft) |
| Backplane Power Requirement | 1.2 A at 5 VDC |
| Weight | 0.82 kg |
| Category | PLCs / Machine Control |
Frequently Asked Questions
Q: Can an SLC 500 processor initiate a message request to a PLC-5 device when the 1785-KA5 is set to gateway mode?
A: No. In gateway mode, DH+ devices must initiate all communication requests, while SLC processors on the DH-485 link function as responders only.
Q: What baud rates are supported on the DH-485 side of the network?
A: The DH-485 network channel supports selectable baud rates ranging from 300 bps up to 19.2 Kbps, configured via onboard DIP switches.
