Teledesign Systems Inc TS4000EH Manuel D’Utilisation
TS4000 Radio Modem User’s Manual
AirNet Packet Protocol
53
Configuration Parameter
Setting
Repeater B Site
Modem Address: Individual
3
CSMA MAC Setup: Data Pkts: Min Idle Slots
4
CSMA MAC Setup: Relay Pkts: Min Idle Slots
1
Store and Forward Repeater Operation: All Packets
Relay All
Repeater C Site
Modem Address: Individual
4
CSMA MAC Setup: Data Pkts: Min Idle Slots
4
CSMA MAC Setup: Relay Pkts: Min Idle Slots
2
Store and Forward Repeater Operation: All Packets
Relay All
Repeater D Site
Modem Address: Individual
5
CSMA MAC Setup: Data Pkts: Min Idle Slots
4
CSMA MAC Setup: Relay Pkts: Min Idle Slots
3
Store and Forward Repeater Operation: All Packets
Relay All
Remote Sites
Modem Address: Individual
10+ (each remote must have a unique
address)
address)
CSMA MAC Setup: Data Pkts: Min Idle Slots
Base packet transmit slots + Largest Relay
Pkt: Min Idle Slot
Pkt: Min Idle Slot
Equations:
Base packet transmit slots = Packet Transmit Time / Slot Time
Packet Transmit Time = {9 * [Max Outbound Message Length (in bytes) + 14] * Overhead / Air
Rate (in kbps)} + Radio Tx Attack Time (in ms)
Overhead = 1 if Coding (FEC) is Unchecked
Overhead = 1.5 if Coding (FEC) is Checked
Overhead = 1.5 if Coding (FEC) is Checked
Slot Time = 1.5 * Radio Transmit Attack Time
Example: Remote Sites
Max Message Length for Modbus protocol = 255 bytes
Radio Tx Attack Time = 20ms (this value can be read on the Radio Hardware Screen)
Air Rate = 9.6 kbps (this is configured on the Radio tab)
Coding = Unchecked (this is configured on the Radio tab)
Largest Relay Pkt: Min Idle Slots = Repeater B: Relay Pkts: Min Idle Slots = 3
Slot Time = 1.5 * 20ms = 30ms (this is configured on the Packet General tab)
Packet Transmit Time = [9 * (255 + 14) * 1 / 9.6] + 20 = 273ms
Base packet transmit slots = 273/30 = 10 (rounded up from 9.1)(this value must be rounded up)
CSMA MAC Setup: Data Pkts: Min Idle Slots = 10 + 3 = 13
Radio Tx Attack Time = 20ms (this value can be read on the Radio Hardware Screen)
Air Rate = 9.6 kbps (this is configured on the Radio tab)
Coding = Unchecked (this is configured on the Radio tab)
Largest Relay Pkt: Min Idle Slots = Repeater B: Relay Pkts: Min Idle Slots = 3
Slot Time = 1.5 * 20ms = 30ms (this is configured on the Packet General tab)
Packet Transmit Time = [9 * (255 + 14) * 1 / 9.6] + 20 = 273ms
Base packet transmit slots = 273/30 = 10 (rounded up from 9.1)(this value must be rounded up)
CSMA MAC Setup: Data Pkts: Min Idle Slots = 10 + 3 = 13