© Microhard Systems Inc.
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6.0 Configuration
Values
S217
Protocol Type
0 transparent
1 MODBUS RTU
2 DF1 protocol, full-duplex,
with address filtering
For most applications, the default value of 0 - resulting in transparent operation -
will be maintained in this register. Setting this register to a value of 1 specifies
MODBUS operation, in which the modem will frame the output data and comply with
MODBUS specifications. S217=2 configures the modem for DF1 filtering. In this
mode, the PLC’s address must match the Unit Address of the modem. Data not
intended for a specific PLC/Modem pairing will be blocked from passing through the
modem to the attached PLC.
Values
S232 Maximum Buffer in Storage
1-255
200
This register defines the maximum number of packets sent on the user serial port that
can be stored in the buffer.
The longer the Sniff Timeout
(duration), the more assured it
is that the Remote modem will
‘find’ an upstream unit when it
is desired to wake up the
system, however more power
will be consumed.
Values
S237
Sniff Timeout
hops
1-255
10
This register applies only to Remote modems.
Defines how many hops the unit will sniff for upon expiry of the Sleep Time (S144).
The Sniff Timeout (sniff duration) in milliseconds is calculated as follows:
Sniff Timeout=S237 (hops) x hop interval (per S109)
Example: S237=20, S109=9 (=20ms)
Sniff Timeout = 20 (hops) x 20ms per hop = 400ms