Bronkhorst IQ+FLOW (till 01-07-2013) - Manual (Page 25)

9.17.045 page 25
4.2 Special instrument features
4.2.1 Auto zeroing
To start the auto zero-procedure by digital operation two parameters should be written:
Control Mode
Type Access Range FlowDDE FLOW-BUS Modbus
Unsigned char RW 0…255 12 1/4 0x0024/37
Calibration Mode
Type Access Range FlowDDE FLOW-BUS Modbus
Unsigned char RW 0…255 58 115/1 0x0E61/3682
Value Mode Instrument action
0 Idle Idle
9 Auto zero Auto-zeroing
255 Error Idle
Auto-zero procedure:
Step 1: Set ‘Control Mode’ to ‘Calibration Mode’ (value 9)
Step 2: Set ‘Calibration Mode’ to ‘Auto zero’ (value 9)
Step 3: Check ‘Calibration Mode’,
Idle (value 0) Auto-zeroing succeeded
Auto zero (value 9) Auto-zeroing active
Error (value 255) Auto-zeroing failed
4.2.2 Changing default control mode
Instruments are delivered with either analog or digital signal as default, depending on customer’s requirement. After
every (power-up) reset the instrument will return to its default control mode. The default control mode can be
changed with the following parameter:
IOStatus
Type Access Range FlowDDE FLOW-BUS Modbus
Unsigned char RW 0…255 86 114/11 0xF258…0xF259/62041…62042
Bit 6 [7…0] represents the former analog jumper.
1 = default control mode is analog
0 = default control mode is digital
Procedure for changing default digital operation to default analog operation:
• Read ‘IOStatus’
• Add 64 to the read value ]) 40 0 [ ( x OR
• Write ‘IOStatus’
Procedure for changing default analog operation to default digital operation:
• Read ‘IOStatus’
• Subtract 64 from the read value ]) 40 0 [ ( x AND
• Write ‘IOStatus’