Description
Product Core Brief
- Model: MOLEX SST-PFB3-VME, SST-PFB3-VME-2-E, PB3-VME-2-E
- Brand: Molex / SST (now part of HMS Networks)
- Series: PFB3 VMEbus Communication Modules
- Core Function: PROFIBUS DP communication interface for VMEbus systems
- Type: VMEbus Communication/Interface Module
- Key Specs: VMEbus slot module PROFIBUS DP Master/Slave 9-pin D-Sub port Supports 9.6 kbps–12 Mbps
MOLEX SST-PFB3-VME SST-PFB3-VME-2-E PB3-VME-2-E
Key Technical Specifications
- Bus Standard: VMEbus 6U / VME64 architecture
- Communication Protocol: PROFIBUS DP (Master and Slave configurable)
- Baud Rates: 9.6 kbps to 12 Mbps
- Host Interface: VMEbus A24/A32 addressing, IRQ support
- Connector: DB9 (9-pin D-Sub) for PROFIBUS DP
- Isolation: Optical isolation on PROFIBUS port (~500 VDC)
- Operating Temp: 0 °C to +60 °C typical (extended options available)
- Power: Draws from VME backplane (+5 V nominal)
- Diagnostics: PROFIBUS network fault detection and reporting
- Form Factor: Single VME slot, 6U form factor
Installation & Configuration Guide
Preparation (≈10 min)
⚠️ Safety First
- Coordinate maintenance window; ensure the host VME system is in a safe state.
- Power down the VME chassis and isolate all power feeds (lockout/tagout).
- Gather tools: insulated screwdrivers, static wrist strap, labels, camera.
Documentation
- Photograph existing bus configuration, card positions, and wiring.
- Record current PROFIBUS node address and baud rate.
Removal of Old Module (≈5 min)
- Confirm DC power to the VME chassis is removed.
- Label any external PROFIBUS cabling.
- Unscrew and extract the old SST-PFB3-VME or PB3-VME-2-E card.
- Check VME backplane connectors for bent pins/debris.
A small thing but important: bent pins here cause intermittent bus errors.
Install New SST-PFB3-VME (≈10 min)
- ESD protection on, unpack the new module.
- Match the exact model (SST-PFB3-VME or SST-PFB3-VME-2-E) for your application.
- Insert into the designated VME slot, assert even pressure until seated.
- Secure retention screws.
- Reconnect PROFIBUS cabling to the DB9 connector.
Checklist
- Correct slot & orientation
- DB9 PROFIBUS port connected
- Backplane connector fully seated
Power-On & Testing (≈15–20 min)
- Restore power to the VME chassis.
- Observe module status LEDs (if present) for error indicators.
- Launch PROFIBUS diagnostic/configuration software.
- Verify node address, baud rate, and cyclic data exchange.
Test plan:
- Confirm master/slave role operation.
- Poll PROFIBUS slaves for status and cyclic I/O.
- Monitor for 20–30 min for stable data transfer without errors.
MOLEX SST-PFB3-VME SST-PFB3-VME-2-E PB3-VME-2-E
Customer Cases & Industry Applications
Case 1: Process Control Integration in Legacy Automation System
Situation:
A chemical facility with a legacy VME-based control rack needed to add PROFIBUS connectivity for remote I/O expansion. The original interface card failed, halting fieldbus communication.
Task:
Minimize downtime and restore reliable PROFIBUS DP data exchange.
Action:
A buffer stock SST-PFB3-VME-2-E was installed from inventory, configured as a PROFIBUS DP master at the existing baud rate, and tested with system diagnostics.
Result:
Data exchange was restored within one shift, operations resumed without extended outages, and lead time variability drove a reassessment of min/max stocking levels for this module.
Case 2: Power Generation Diagnostics Upgrade
Situation:
A power generation plant needed deeper diagnostics on its PROFIBUS network tied to legacy VME analytics. The existing interface card lacked adequate fault reporting.
Task:
Deploy a module with enhanced diagnostics and network visibility.
Action:
The PB3-VME-2-E was stocked and installed in a spare VME slot, configured in dual master/slave mode to facilitate both operation and monitoring.
Result:
Network faults were quickly identified and resolved, reducing unplanned maintenance, and cross-site sharing was implemented to optimize stocking.
Frequently Asked Questions (FAQ)
Q1: What is the SST-PFB3-VME-2-E / PB3-VME-2-E?
A: It’s a VMEbus communication interface card that bridges a VME-based host system to PROFIBUS DP field networks, capable of master or slave operation.
Q2: Is it still supported by the manufacturer?
A: The SST-PFB3-VME series has been discontinued by Molex; current availability depends on surplus inventory and 3rd-party stock.
Q3: What protocols does it support?
A: Primarily PROFIBUS DP from 9.6 kbps up to 12 Mbps for cyclic and acyclic data communications.
Q4: Does it draw external power?
A: No external supply is needed; it draws power from the VME backplane (+5 V nominal).
Q5: How should this part be stocked?
A: Given its legacy status and lead time variability, keep at least one on-site buffer in critical control racks; optimize reorder points based on outage history.
