aci eRCM Express, Руководство пользователя

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mCore Firmware Ver 01.10 Ver 2019-Oct-29 Page 38 of 97
Modbus Read/Write Pseudo Code Examples
Sending Data to eRCM Express™:
Modbus.Data(1) = 1 // Current Hardware Load Step
Modbus.Data(2) = 206.5 // Current Suction Pressure (psiG) into First Stage
Modbus.Data(3) = 318.9 // Current Discharge Header Pressure (psiG) out of Last Stage
Modbus.Data(4
) = 1158 // Unit’s Speed (RPM)
Modbus.Data(5) = 74.5 // First Stage Suction Gas Temperature (degF)
Modbus.Data(6) = 128.2 // Second Stage Suction Gas Temperature (degF), when required
Modbus.NumberOfValues = 6 // 6 is the number of input values (1 Value = two 16-bit regs)
Modbus.Address = 40001 // 40001 is the starting address for the input values
Modbus.WriteData() // Write new input values to the Modbus registers.
Force eRCM Express™ to Recalculate New Compressor Performance:
Modbus.Data(1) = 1 // “1” is fl ag to recalculate
Modbus.NumberOfValues = 1 // 1 is the number of input values (1 Value = two 16-bit regs)
// Reg#40075 is ideal if only using the shorter Quick Writes list (smaller Modbus block)
Modbus.Address = 40075 // 40075 is the address for
ForceERCMExpressCalculations
OR Modbus.Address = 40273 // 40273 is the address for ForceERCMExpressCalculations
Modbus.WriteData() // Write value to the Modbus register.
Waiting for eRCM Express™ to Complete Calculations – Using IsKernelBusy Method:
DIM eRCMExpressCount as Integer
Modbus.NumberOfDataValues = 1
Modbus.Address = 40275 // The address of the "IsKernelBusy" register.
// Will return false (0) when eRCM Express has completed
// all of its performance and safety calculations.
// This usually takes less than 250 ms.
eRCMExpressCount = 0
DO
Sleep 20 // Sleep 20 ms
Modbus.ReadData() // Read data in the "IsKernelBusy" register.
If Modbus.Data(1) = 0 Then Exit DO // If 0, then calculations are now complete.
eRCMExpressCount = eRCMExpres 1
LOOP UNTIL eRCMExpressCount > 15 // Prevent Infinite Loop
IF eRCMExpressCount > 15 THEN
MSG “CRITICAL ISSUE: eRCM Express Unit does not appear to be returning data.”
// NOTE: If a Gateway device is between eRCM Express and PLC, then you may need
// to wait longer for updates to happen.
ELSE
…Now proceed with reading in eRCM Express data…
END IF
Waiting for eRCM Express™ to Complete Calculations – 250 ms Method:
Sleep 250 // Sleep at least 150 ms. eRCM Express will be done by then for MOST models.
// If model has lots of load steps (20+) or multiple stages (2+) then
// more time may be required to finish all of the calculations.
// 250-350 is usually the MOST you need to wait.
…Now proceed with reading in eRCM Express data…