Hach MET ONE 6000P Manuel D'utilisation page 17

RL = value of the load resistor in ohms
The expected output voltage when the full-scale channel count is
1000 with a 100, 250 and 500-ohm resistor is shown in
9. To do the test again, do steps 7–8.
10. When the Status value changes from "Stop" to "Count", temporarily
put a cover over the sample probe to cause a flow alarm.
11. While a flow alarm is active, measure the voltage across the load
resistors for each channel.
12. Use the equation that follows to calculate the expected voltage.
Make sure that the measured and calculated voltages agree.
Voltage = < (0.002 × RL)
Where: RL = value of the load resistor in ohms
Example: for a 100-ohm resistor, the voltage should be less than
0.20 V.
13. Remove the cover from the sample probe.
14. On the Basic Setup tab, change the settings back to the previous
values.
15. Click Save Settings.
Table 5 Output voltage with 100, 250 and 500-ohm resistors
Sample count 100 Ω
0 0.40 V
100 0.56 V
200 0.72 V
300 0.88 V
400 1.04 V
500 1.20 V
600 1.36 V
700 1.52 V
800 1.68 V
Table 5.
250 Ω 500 Ω
1.00 V 2.00 V
1.40 V 2.80 V
1.80 V 3.60 V
2.20 V 4.40 V
2.60 V 5.20 V
3.00 V 6.00 V
3.40 V 6.80 V
3.80 V 7.60 V
4.20 V 8.40 V
Table 5 Output voltage with 100, 250 and 500-ohm resistors
(continued)
Sample count 100 Ω
900 1.84 V
1000 2.00 V
RS485 serial output with Modbus RTU protocol
Instruments with the RS485 Modbus communication option use industry-
standard Modbus RTU protocol. In this communication mode, a series of
registers hold data about measurement results and operation
parameters.
When a ModbusTCP connection is made, the user can use all the
configuration options in the Modbus register map. Refer to the company
website for the Modbus register map. Write drivers to communicate with
the instrument through these registers with the Modbus RTU protocol.
The RS485 serial network circuit supplies communications for a
maximum of 32 instruments and a control computer. Only one
instrument can transmit data at a time. Each instrument must have a
unique instrument address.
1. Turn the instrument over. The DIP switch is on the bottom of the
instrument.
2. Change the DIP switch setting to select a unique network address for
the instrument. Refer to Table
Note: Address 0 can only be used with FXB protocol. Address 0 is reserved for
use as a broadcast address for Modbus RTU. If address 0 is set with Modbus
protocol, the instrument will use address 1.
Table 6 DIP switch settings for network address
Network address Switch 1 Switch 2
0 Off Off
1 On Off
2 Off On
3 On On
250 Ω 500 Ω
4.60 V 9.20 V
5.00 V 10.00 V
6.
Switch 3 Switch 4 Switch 5
Off Off Off
Off Off Off
Off Off Off
Off Off Off
English 17