R&S RTO6 - Page 862

Protocol analysis
R&S
®
RTO6
862User Manual 1801.6687.02 ─ 05
●
Alternate modes can be defined through vendor defined messages, which allows
for USB connector pins to be used for purposes other than USB
Message types
In the USBPD protocol, a power delivery connection can be made between a port that
supplies power (source) and a port that consumes power (sink). They communicate
with each other through messages. The USBPD specification defines three message
types:
●
Control messages: 16-bit messages used to control the messages between the
port partners or transfer messages with no extra data. A control message consists
of a message header and a CRC.
●
Data messages: 48 bit to 240 bit messages used to transfer information between
port partners. A data message consists of a message header and several data
objects. The information that a data object carries is defined by the message type
of the message header
, see
Table 13-42.
●
Extended messages: can have a different length up to the defined maximum length
of an extended message. It is used to transfer information between port partners.
The information that the extended message carries is defined by the message type
of the message header, see Table 13-42.
Frame packet types
All frame types are listed below. The frames listed above consist of individual sets of
fields. Some frames only contain one field, others are much longer.
The frame types are sorted according to the message type.
Table 13-42: Frame packet types
SCPI Description Message type
ALRT Alert message Data
BATT Battery status Data
BIST Built in self-test Data
RQST Request Data
SINK Sink capabilities message Data
SRC Source capabilities message Data
VEND Vendor defined message Data
CTRL Control Control
DATA Data Data
LOWP Low power Low power
TEST Test frame Test
RESet Reset frame Reset
XBAC Battery capabilities Extended
XFRS Firmware update response Extended
USBPD (option R&S RT
O6-K570)