WirelessHART TDMA Superframe Workbench

Step through an industrial TDMA schedule and watch each link hop to a channel

Learner-ready WirelessHART TDMA animation with a superframe cursor, channel-hopping table, blacklist controls, routing modes, time-sync drift estimate, diagnosis cards, and mobile-ready learning support.

Animation WirelessHART TDMA Channel Hopping

WirelessHART TDMA Superframe Workbench

Step through an industrial wireless schedule. Each 10 ms slot chooses one communication link, then maps that link to a physical IEEE 802.15.4 channel using the active channel table and a channel offset.

Slot Duration 10 ms fixed TDMA window

Channel Pool IEEE 802.15.4 channels 11 to 25

Scheduler Central Network Manager

Teaching Model ASN plus channel offset

Scenario

Routing View

Graph routes give the device a precomputed set of next hops. Source routes carry a more explicit path. Shared slots are mainly for join or management traffic.

Schedule Controls

Displayed slots

10 slots

Channel offset bias

+0

Time since sync

10 s

Show device and slot labels

Channel Blacklist

Mark persistent bad channels. The workbench recomputes the active channel table before each hop.

Routine monitoring schedule

A centrally managed superframe reserves slots for field data, forwarding, broadcast sync, shared access, and retry opportunities.

Deterministic slot active

Slot 0: Gateway broadcast sync The active link is drawn in teal. The token moves along the scheduled transmitter and receiver for the current 10 ms slot.

ASN 1200

Current Slot 0 / 9

Physical Channel CH 11

Slot Type Broadcast

Dedicated Broadcast Shared Retry Idle

Active Channel Table 14 / 15 channels CH 20 is blacklisted.

Estimated Path Delay 20 ms Two scheduled hops to the gateway.

Sync Drift Estimate 0.40 ms At +/-40 ppm after 10 s.

Reliability Move Hop around interference Channel diversity plus reserved time.

What Is Happening

1

Manager schedules the linkA central Network Manager assigns the time slot, receiver, and channel offset.

2

Devices share timeAll devices use the Absolute Slot Number, so slot boundaries line up.

3

Channel is selectedThe ASN and channel offset index into the active channel table.

4

Message and ACK fit in the slotThe 10 ms window includes transmit time, turnaround, ACK, and guard time.

5

Retries or graph routes recoverIf a channel or link is poor, later slots and alternate paths keep the plant visible.

Diagnosis

How to Read This Animation

1. Watch the highlighted slot: it is the only link allowed to transmit in that 10 ms window.
2. Read the ASN and channel: the same slot in the next superframe can land on a different physical channel.
3. Blacklist a channel and notice that hopping continues across the remaining active channels.
4. Compare graph and source routing: both can be scheduled, but graph routing gives redundant next-hop choices.

Technical Quick Reference

Slot durationWirelessHART uses 10 ms TDMA slots for scheduled link activity.

Channel set2.4 GHz IEEE 802.15.4 channels 11 to 25, with blacklisting for persistent interference.

ASNThe Absolute Slot Number is shared network time and advances each slot.

Channel offsetA scheduled link uses an offset with ASN to choose a physical channel from the active table.

Dedicated slotReserved for a specific transmitter and receiver, so normal traffic avoids contention.

Shared slotUsed for join or management access where contention and backoff can still occur.

Try Checks

• Wi-Fi interference: choose that scenario, then blacklist CH 21. Does the active channel count and current channel update together?
• Safety alarm: step through the first three slots. The critical path should reach the valve command quickly.
• Shared mode: switch to Shared and notice the diagnosis changes from collision-free certainty to managed contention.
• Time sync: move the sync-age slider to 30 s. The drift estimate should grow, but still fit the 10 ms slot model.

Model Boundaries

• This is a teaching model. The displayed 6 to 14 slot schedule is a compact excerpt; production schedules can contain many more slots.
• Real WirelessHART uses a standardized pseudo-random hop sequence and detailed schedule tables, not this exact UI formula.
• Blacklisting removes persistently poor channels from the channel table. It does not guarantee perfect delivery if links, antennas, or time sync are bad.
• The delay estimate counts scheduled 10 ms hops in the displayed path. It does not model full protocol overhead, retries, security processing, or plant controller logic.
• Shared slots are deliberately shown as less deterministic because they can involve contention before a device receives dedicated resources.