HK Instruments DPT-MOD Series Installation Instructions page 4

turns on and the display reads "zeroing" (display option only). (see
Figure 6)
c) The zeroing of the device will proceed automatically. Zeroing is
complete when the LED turns off, and the display reads 0 (display
option only).
d) Reinstall the pressure tubes, ensuring the High pressure tube is
ZEROING THE DEVICE
CONTINUED
connected to the port labeled +, and the Low pressure tube is
connected to the port labeled −.
Press down button
LED
2) Autozero calibration
If the device includes the optional autozero circuit, no action is re-
quired.
Autozero calibration (-AZ) is an autozero function in the form of an
automatic zeroing circuit built into the PCB board. The autozero cali-
bration electronically adjusts the transmitter zero at predetermined
time intervals (every 10 minutes). The function eliminates all output
signal drift due to thermal, electronic or mechanical effects, as well as
the need for technicians to remove high and low pressure tubes when
performing initial or periodic transmitter zero point calibration. The
autozero adjustment takes 4 seconds after which the device returns to
its normal measuring mode. During the 4 second adjustment period,
the output and display values will freeze to the latest measured value.
Transmitters equipped with the autozero calibration are virtually
maintenance free.
3) Via Modbus register
Make sure there is no pressure in the duct when the zeroing is done
via Modbus register.
STEP 5: MODBUS REGISTERS
Function code 04 - Read input register
Register Parameter description
3x0001 Program version
3x0002 Pressure reading
3x0003 Flow m3/s
3x0004 Flow m3/h
3x0005 Flow cfm
3x0006 Flow l/s
3x0007 Velocity m/s
3x0008 Velocity f/min
Function code 05 - Write single coil
Register Parameter description
0x0001 Zero point calibration
Function code 03 - Read input holding register
Register Parameter description
4x0001 Manufacturer
4x0002 Formula unit (Manufacturer=7)
4x0003 K-factor integer
4x0004 K-factor decimal
4x0005 Response time
Copyright HK Instruments 2020
Figure 3
LED turns ON
Display reads "Zeroing"
Data Type Value Range
16 bit 0...9900 0,00...99,00
16 bit -250...2500/7000 -250...2500/7000 Pa
16 bit 0...10000 0...100 m3/s
16 bit 0...30000 0...30000 m3/h
16 bit 0...30000 0...30000 cfm
16 bit 0...3000 0...3000 l/s
16 bit 0...1000 0...100 m/s
16 bit 0...5000 0...5000 f/min
Data Type Value Range
Bit 0 0...1 On - Off
Data Type Value Range
16 bit 0...7 0...7
0: m3/s, 1: m3/h, 2: cfm, 3: l/s,
16 bit 0...5
4: m/s, 5: f/min
16 bit 0...9999 0...9999
16 bit 0...999 0...999
16 bit 1...20 1...20 s
MODBUS REGISTERS
Function code 06 - Write single register
Register Parameter description
4x0001 Manufacturer
4x0002 Formula unit (Manufacturer=7)
4x0003 K-factor integer
4x0004 K-factor decimal
4x0005 Response time
Function code 16 - Write multiple registers
Register Parameter description
4x0001 Manufacturer
4x0002 Formula unit (Manufacturer=7)
4x0003 K-factor integer
4x0004 K-factor decimal
4x0005 Response time
-40C model: operation in cold environment
The lid of the device has to be closed when the operation temperature
is below 0 °C. The display needs 15 minutes to warm up if the device
is started in temperature below 0 °C.
NOTE! The power consumption rises and there can be an additional
error of 0,015 volts when the operation temperature is below 0 °C.
RECYCLING/DISPOSAL
The parts left over from installation should be
recycled according to your local instructions.
Decommissioned devices should be taken to a
recycling site that specializes in electronic waste.
WARRANTY POLICY
The seller is obligated to provide a warranty of five years for the delivered
goods regarding material and manufacturing. The warranty period is con-
sidered to start on the delivery date of the product. If a defect in raw mate-
rials or a production flaw is found, the seller is obligated, when the product
is sent to the seller without delay or before expiration of the warranty, to
amend the mistake at his/her discretion either by repairing the defective
product or by delivering free of charge to the buyer a new flawless product
and sending it to the buyer. Delivery costs for the repair under warranty
will be paid by the buyer and the return costs by the seller. The warranty
does not comprise damages caused by accident, lightning, flood or other
natural phenomenon, normal wear and tear, improper or careless handling,
abnormal use, overloading, improper storage, incorrect care or reconstruc-
tion, or changes and installation work not done by the seller or his/her
authorized representative. The selection of materials for devices prone to
corrosion is the buyer's responsibility, unless otherwise is legally agreed
upon. Should the manufacturer alter the structure of the device, the seller
is not obligated to make comparable changes to devices already purchased.
Appealing for warranty requires that the buyer has correctly fulfilled his/
her duties arisen from the delivery and stated in the contract. The seller will
give a new warranty for goods that have been replaced or repaired within
the warranty, however only to the expiration of the original product's war-
ranty time. The warranty includes the repair of a defective part or device,
or if needed, a new part or device, but not installation or exchange costs.
Under no circumstance is the seller liable for damages compensation for
indirect damage.
www.hkinstruments.fi
CONTINUED
Data Type Value Range
16 bit 0...7 0...7
0: m3/s, 1: m3/h, 2: cfm, 3: l/s,
16 bit 0...5
4: m/s, 5: f/min
16 bit 0...9999 0...9999
16 bit 0...999 0...999
16 bit 1...20 1...20 s
Data Type Value Range
16 bit 0...7 0...7
0: m3/s, 1: m3/h, 2: cfm, 3: l/s,
16 bit 0...5
4: m/s, 5: f/min
16 bit 0...9999 0...9999
16 bit 0...999 0...999
16 bit 1...20 1...20 s
Installation version 7.0 2020