Normal Speed Connection To Telesafe Rtu - Bell 5902 Hardware Manual

TeleSAFE RTUs implement the carrier detect and loss delays, RTS/CTS delays, CTS-Hold and anti-
streaming in software registers. The parameters shown in the table below provide reliable operation
with low error rates, on high quality lines. Due to the shorter delay times than the default
configuration, throughput is significantly higher. Real-world applications may require longer delays.
TeleSAFE
Register
S2:
CTS-On Delay
S4:
Transmit-On
Gap Time
S9:
Carrier Detect
Delay Time
S10:
Carrier Loss
Time
This configuration was tested with a TeleSAFE RTU polling a SmartWIRE I/O system using
Modbus RTU protocol. If too many errors are experienced, increase the RTS/CTS delay of both
modems. If this does not correct the problem, increase the carrier detect delay of both modems.
Ensure that the carrier detect delay is less than the RTS/CTS delay of the other modem.
5.3.6

Normal Speed Connection to TeleSAFE RTU

Use this configuration to connect to a TeleSAFE 6000 or TeleSAFE 6000-16EX RTU with a model
6902 modem, or to a TeleSAFE VS/3 RTU. Both modems are half duplex Bell 202 modems, for use
on two or four wire networks or radios. They have a radio key control output. Soft carrier turn-off
and radio carrier detect are not implemented.
TeleSAFE RTUs implement the carrier detect and loss delays, RTS/CTS delays, CTS-Hold and anti-
streaming in software registers. If these 5902 modem settings do not produce reliable operation, it
may be necessary to increase the RTS/CTS delay, and/or reduce the values in the TeleSAFE RTUs
S9 and S10 registers.
TeleSAFE
Register
S2:
CTS-On
Delay
S4:
Transmit-On
Gap Time
5902 Bell 202 Modem Hardware Manual
October 19, 2007
5902 TeleSAFE
Terminology
Register
RTS/CTS 33 ms
Delay
S2=4
(CS0/CS1)
CTS Hold 50 ms
(CSH) S4=6
Carrier Detect 16.6 ms
Delay
S9=2
(CD0/CD1)
Carrier Loss 16.6 ms
Delay
S10=2
(CL0/CL1)
5902 TeleSAFE
Terminology
Default
RTS/CTS 116.2 ms
Delay
S2=14
(CS0/CS1)
CTS Hold 66.4 ms
(CSH) S4=8
5902
Setting
50 ms
CS0 closed
CS1 open
1 ms
CSH open
SCT - none
SC0 open
SC1 open
19 ms
CD0 open
CD1 open
6 ms
CL0 open
CL1 open
5902
Setting
125 ms
CS0 open
CS1 closed
CSH - 8 ms
CSH closed
SCT - 37.5
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