Tandem Hoist / Trolley Ezcom (Speed / Command Syncing) - Hitachi WJ200 Instruction Manual

Tandem hoist / trolley EZCOM can be used when 2 hoists / trolleys are used in tandem operation and require the frequency,

command status, and run status to sync between each hoist.

The VFD's will need to be configured to communicate between each other and the internal logic activated. A 2-wire shielded cable is

required to connect between the VFD's SN/SP RS485 terminals (Belden 9538 type cable is recommended). Typically, A/B relays will

be used to supply an input to the VFD to activate the syncing logic when in tandem mode, digital input EA is used.

HOW IT WORKS – The VFD's use the SN/SP RS485 terminals to send frequency, drive status, and command status Modbus registers

values between each other. While in sync mode the VFD's compare the directional commands based on conditional internal logic,

which ensures if a hoist / trolley reaches a limit, or loses a command signal the opposite hoist will follow the command. While in

tandem mode the VFD's also compare frequency values and always sync to which VFD has the lowest frequency value, this ensures

the set frequencies always match.

NOTE – If the VFD's are configured for EZCOM tandem sync (P116 > 0) and the EZCOM communication is disconnected (d025 = 9999)

the hoist / trolley will ignore all directional commands even when in individual mode and the communication disconnection must be

addressed.

TROUBLESHOOTING EZCOM COMMUNICATION DISCONNECTION (d025 = 9999) – Use the VFD monitor parameter d025 to monitor

the EZCOM communication disconnection. If the value shown in d024 = 9999 then the communication is disconnected or timed out

or not configured correctly. Check the wiring between the VFD's SN & SP terminals. Also make sure the VFD's power up at the exact

same time or use a digital input to active the EZCOM communication by configuring one of the available digital inputs to 81:485 Start

if power cannot be verified at the same time. Verify EZCOM parameters are configured correctly using the EZCOM parameter chart.

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