RAD-....-IFS
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PHOENIX CONTACT
105542_en_05
6.6.10
RSSI signal and error code registers
The RSSI values indicate the received signal strength on the wireless module. You can read
the RSSI values via the serial interface of the master wireless module (RAD ID = 01) using
Modbus/RTU commands. The RSSI values of all wireless modules in the network are within
address range 35001 ... 35250.
Bit 08 = error on IFS bus
If an error is present on the IFS bus, the register value is 1 (e.g., local bus error, because the
input or output module is disconnected from the DIN rail connector). If no error is present on
the IFS bus, the register value is 0.
–
Bits 9 ... 15 are reserved.
–
Values <255 indicate the RSSI value in -dBm.
–
Value 255 means that the RSSI value is invalid or the device cannot be reached.
Example for reading the RSSI register of the station with RAD ID = 2:
Function code 04, start address 5001 (hex1389)
Table 6-17
RSSI signal and error code registers
Address range
35001 ... 35250
Modbus function code
fc 04
Address
Wireless module
High byte
Low byte, RSSI value
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00
35001
RSSI - RAD ID = 1
(master)
Reserved
IFS
X
X
X
X
X
X
X
X
35002
RSSI - RAD ID = 2
Reserved
X
X
X
X
X
X
X
X
...
...
Reserved
X
X
X
X
X
X
X
X
35250
RSSI - RAD ID = 250
Reserved
X
X
X
X
X
X
X
X
