16
When several devices are connected in the same loop, each device must be assigned a
unique address. If two devices share the same address, Communicator will not be able to
find the devices of this address, and then you will have to connect the device separately to
correct the polling address. HART Protocol defines the communication mode of
connecting several devices in the same loop as multidrop mode. Under multidrop mode,
the current in the loop will not be 4~20mA, but the sum of the output current from all the
devices.
4.7.2 Battery
Follow the below operation to access Battery:
Main Menu→3 Battery.
This function will check the remaining battery capacity automatically and display it in %.
When the battery capacity is too low, please change battery at once to avoid influence on
the normal use of the Communicator.
4.7.3 Polling
Follow the below operation to access Battery Capacity:
Main Menu→4 Polling.
When several devices are connected in the same loop (multidropped), you can achieve
the communication with the required device by polling (Figure 13).
Figure 13 Polling Menu
Item 1 is Single Polling, you can select any address between 0 and 15 to communicate
；
Item 2, item 3 and item 4 is group polling; address 0~15 has been divided into three group.
When a device is found by polling, the Online Menu displays; or go back to the original
interface, and you should have to select the polling address once again.
You could only communicate with the first device found (smallest address) by group
polling. To communicate with the other devices found (bigger address) by group polling,
you should have to perform Single Polling.
Polling
1 Single Polling
2 Polling Addr0-7
3 Polling Addr8-15
4 Polling Addr0-15
