TMDSPLCKITV4-CEN: G3-PLC LMAC mode

Shailja Shukla

Part Number: TMDSPLCKITV4-CEN
Other Parts Discussed in Thread: TMS320F28PLC84, TMS320F28062

Hello,

Considering the configuration: (TMS320f28PLC84 PLC modem and TMS320F28062 application MCU), I understand using the LMAC binary from the G3-DC-SDK package (www.ti.com/.../ti-plc-g3-dc) enables the nodes to function in the LMAC mode. Further, I have following three questions :-

1) Can the LMAC mode be used with multiple nodes by configuring one as TX and other nodes as RX?

I understand the message transfer can happen only if the nodes are within the transmission range, since there won't be any network formation to enable multiple hops.

2) I see there are ACKs with the LMAC mode [MAC_STAT_NO_ACK (0xE9) is one of the possible status for DATA_TRANSFER.confirm] (DC v4.8 docs: TI_plcSUITE_G3_dc_host_msg.pdf).

Is it possible to disable the ACKs ?

3) How does the addressing work in the LMAC mode. Are the messages sent in broadcast ? This would help explain in case of multiple RX nodes, how would each node respond with an ACK to the sender node ?

Any clarification would be highly appreciated.

Kind regards,
Shailja

over 8 years ago

0 Shailja Shukla over 8 years ago

Prodigy 240 points

Hello,

I would really appreciate if someone could answer the above questions.

Also while testing LMAC TX and RX functions in Zero Config GUI for TMDSPLCKITV4-CEN nodes, I see there are two options when I start the LMAC TX function -

1) Check-box for Primary Interface

2) Format version

I am adding a screenshot for reference. Is there an explanation given somewhere for these options ?

Kind regards,
Shailja

0 Shailja Shukla over 8 years ago in reply to Shailja Shukla

Prodigy 240 points

Dear all,

I am not able to setup the LMAC mode with a custom board, which has a configuration: (TMS320f28PLC84 PLC modem and TMS320F28062 application MCU).

I follow the PLC initialization setup done with TMDSPLCKITV4-CEN nodes for running LMAC TX-RX functions, but I can't seem to receive or transmit any messages from my custom board. The custom board works fine with MINI DC configuration, so the problem doesn't lie with the hardware, or the UART implementation. I think the messages are terminated at the PLC modem, may be because of wrong initialization.

So are there any documents on how to use the LMAC mode, explaining the PLC initialization setup, transfer of messages, etc.

I would really appreciate if someone could answer my queries, I am stuck at this for more than a month.

Kind regards,
Shailja

0 MEGHANA MANAVAZHI over 8 years ago

TI__Genius 10345 points

hi Shailja ,

1. Yes we can have one TX & multiple RX . As long as the data is provided with the complete address details in the expected formats it should not matter if the data is sent to 1 node or many nodes.

2. Yes there is an ack_req ( acknowledgement req) bit in the FC ( frame control field ) header.
if that is set to 0 , no ACKs would be sent back . There is not PIB for it though.

3.Yes they can be sent in broadcast. They can also be in unicast.

0 MEGHANA MANAVAZHI over 8 years ago in reply to Shailja Shukla

TI__Genius 10345 points

Primary interface is the normal LMAC , but secondary Interface is for a Dual - MAC mode specifically for ARIB band .
In DMAC where we can have both paths for a Base node basenode behavior & LMAC behavior .

www.ti.com/.../TI-PLC-G3-ARIB-SN

0 MEGHANA MANAVAZHI over 8 years ago in reply to Shailja Shukla

TI__Genius 10345 points

Hi Shailja ,

The LMAC mode of SN has not been tested much , you can use the LMAC build part of the DC SDK and try .
There is some level of documentation there .

www.ti.com/.../ti-plc-g3-dc

0 Shailja Shukla over 8 years ago in reply to MEGHANA MANAVAZHI

Prodigy 240 points

Hi Meghana,

Thank you for your reply.

Investigating further into the LMAC mode transfers I see the following raw message exchanged during LMAC TX-RX test on Zero Config GUI:

2017-06-16 09:31:38.4492: Message Sent:

0x00 80 37 00 58 A7 B8 21 01 08 0x00 0C FF FF 03 08 00 FF FF FF

0xFF FF FF 00 00 04 00 01 04 04 0x21 DC 01 55 74 00 00 00 00 00

0x00 FF 02 55 74 00 00 00 00 00 0x00 FF 01 30 31 32 33 35 89

2017-06-16 09:31:38.4492: Sending: (0x00) - G3 DC DataTransfer.Request V1

Interface: Primary

NSDU Handle: 1

ARQ: Enabled

QoS: Standard Priority

Band Selection: CENELEC

Protocol: G3

Power Level: 12

Tone Map: 0xFF FF 03

Resolution: 6 dB

Gain: 1

Modulation: ROBO

TX Coef: 0xFF FF FF FF FF FF

COH: Off

MPDU Payload Length: 4

MPDU:

0x01 04 04 21 DC 01 55 74 00 00 0x00 00 00 00 FF 02 55 74 00 00

0x00 00 00 00 FF 01 30 31 32 33 0x35 89

Is there an explanation for the MPDU payload format for DC? I see the destination and source addressing information is added to the MPDU payload.

However there are 6 octets in the start of the MPDU (from above example highlighted in red: 0x01 04 04 21 DC 01), that are not clear. The format do not match G3-Specification - 802.15.4 MAC layer standard MPDU format either.

Is there a MAC Layer API for DC that I can refer to?

Kind regards,
Shailja