Appendix D. ModBus Management Support and Memory
Map
ROS® v3.11User Guide
131
RMC30
of ports 17–32. In this example, the device only has 20 ports, so byte 6 contains the status
for ports 17-20 starting from right to left. The rest of the bits in register 2 corresponding to the
non-existing ports 21–31 are zero.
Performing write actions using PortCmd:
For example, consider a “Write Multiple Register” request to clear Ethernet port statistics:
0x10
0x00
0x83
0x00
0x01
2
0x55
0x76
0x00
0x50
A bit value of 1 is a command to clear Ethernet statistics on a corresponding port. A bit value
of 0 is a command to “do nothing” on a corresponding port.
The response may look like:
0x10
0x00
0x81
0x00
0x02
D.1.6. Alarm
This format is another form of text description. Alarm text corresponds to the alarm description
from the table holding all of the alarms. Similar to the ‘Text’ format, this format returns ASCII
representation of alarms. Note that alarms are stacked in the RuggedCom device in the
sequence of their occurrence. That is, the first alarm on the stack is Alarm 1, the next latched
alarm in the device is Alarm 2, and so on. You can return the first eight alarms from the stack,
if they exist. A zero value is returned if an alarm does not exist.
D.1.7. PSStatusCmd
This format describes a bit layout for providing the status of available power supplies. Bits 0–
4 of the lower byte of the register are used for this purpose.
Bits 0–1: Power Supply 1 Status.
Bits 2–3: Power supply 2 Status
The rest of the bits in the register do not provide any system status information.
Bit Value
Description
01
Power Supply not present (01 = 1).
10
Power Supply is functional (10 = 2).
11
Power Supply is not functional (11 = 3).
Table D.1. PSStatusCmd Bit Values
The values used for power supply status are derived from the RuggedCom-specific SNMP
MIB.
Read Power Supply Status from device using PSStatusCmd:
In this example, consider a Modbus Request to read multiple registers from location 0x0043.
0x04
0x00
0x43
0x00
0x01
Response may look like:
