Parker PVSG, User Manual

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PVSG User Guide
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6. Communication
The•types•of•communication•available•to•the•PVSG•family•are•Controller•Area•Network•(CAN),•Wi-Fi,•USB•
host/device,•J1708,•LIN,•and•Ethernet.•The•types•and•quantity•of•communication•ports•are•dependent•on•
product•version.
6.1. Controller area network
The•PVSG•has•5•Controller•Area•Network•(CAN)•communication•port(s)•available.•The•PVSG•hardware•
provides•controller•area•network•(CAN)•communication•according•to•the•SAE•J1939•specification,•
making•the•PVSG•compatible•with•any•CAN-based•protocol•through•software.
CAN•communication•is•used•to•communicate•the•status•of•multiple•modules•that•are•connected•to•each•
other•in•the•same•network.
6.1.1. CAN Capabilities
The•CAN•communicates•information•at•a•selectable•rate•from•125•kbps•to•1000•kbps.•Lack•of•regular•
CAN•communication•is•an•indication•that•there•is•either•a•problem•with•a•module•in•the•network,•or•a•
problem•with•the•CAN•bus.
CAN•communication•provides•a•feature•called•Wake•on•CAN,•which•is•a•way•to•provide•power•control•to•
the•PVSG.
Wake•on•CAN•provides•a•low-current•sleep•mode•that•turns•on•the•PVSG•when•a•CAN•message•is•
received•by•the•module.
It•is•not•possible•to•filter•messages•that•are•used•to•turn•on•the•PVSG•using•Wake•on•CAN.•For•this•reason,•
any•message•will•turn•on•the•PVSG.•The•application•software•must•be•written•to•determine•how•the•PVSG•
will•behave•when•it•is•turned•on.
The•following•table•provides•specifications•for•the•CAN:
Item Min Nom Max Unit
Baud rate limitations (hardware) - - 1000 kbps
Baud rate limitations (software) 125 - 1000 kbps
Wake on CAN current draw - - 500 uA
Termination resistor 120 - - Ω
6.1.2. J1939 CAN Installation Connections
The•CAN•connection•for•the•PVSG•should•conform•to•the•J1939•standard.•The•J1939•standard•is•a•robust•
automotive•specification•that•is•a•good•CAN•installation•guideline•even•when•the•J1939•CAN•protocol•is•
not•being•used.
For•a•list•of•J1939•connection•considerations,•refer•to•the•SAE•J1939•specifications•available•through•the•
Society•for•Automotive•Engineers.•SAE•J1939-11•covers•the•physical•aspects•of•the•CAN•bus•including•
cable•type,•connector•type,•and•cable•lengths.
Note:•The•standard•variant•of•the•PVSG•does•not•have•a•CAN•termination•resistor,•which•is•based•on•the•
assumption•that•the•CAN•bus•is•terminated•in•the•harness.
The•following•lists•the•elements•that•are•required•for•a•J1939•CAN•connection:
• • CAN•Cable:•A•shielded•twisted-pair•cable•should•be•used•when•connecting•multiple•modules•to•
the•CAN•bus.•The•cable•for•the•J1939•CAN•bus•has•three•wires:•CAN•High,•CAN•Low,•and•CAN•
Shield•(which•connect•to•the•corresponding•CAN_HIGH,•CAN_LOW,•and•CAN_SHIELD•pins•on•the•