User's Manual

www.lairdtech.com

Laird Technologies

BTM410/411

Bluetooth

AT Data Module

Modem Control and Status Signals

A serial port has DTR, DSR, RTS, CTS, DCD and RI control lines. RTS and CTS are locally controlled to prevent

local buffer overﬂ ow.

The status of DTR, DRS, DCD and RI can be exchanged with the remote peer device. If for example,

the DTR/DSR lines are to be exchanged between the two peers to simulate the performance of a physical

cable, then it is possible to do so. Refer to the description for S Registers 551, 552 and 553 for more details.

Some serial implementations link CTS and RTS to remove the need for handshaking. Ezurio do not

recommend linking CTS and RTS other than for testing and prototyping. If these pins are linked and

the host sends data at the point that the Bluetooth Serial Module deasserts its RTS signal, then there

is a signiﬁ cant risk that internal receive buffers will overﬂ ow which could lead to an internal processor

crash. This will lead to a drop in connection and may require a power cycle to reset the module.

Ezurio recommend that the correct CTS/RTS handshaking protocol be adhered to for proper operation.

APPLICATION

EXAMPLES

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:

(1) This device may not cause harmful interference, and (2) this device must accept any interference received,

including interference that may cause undesired operation.

Changes or modiﬁ cations not expressly approved by the party responsible for compliance could void the user’s

authority to operate the equipment.

To comply with the FCC RF exposure compliance requirements, this device and its antenna must not be

co-located or operating to conjunction with any other antenna or transmitter.

Considerations for OEM integration:

To inherit the modular approval, the antennas for this transmitter must be installed to provide a separation

distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any

other antenna or transmitter.

Co-location with other radio transmitting devices operating concurrently in the same band will require

additional testing and certiﬁ cation.

Designers should note the distinction that the FCC makes regarding portable and mobile devices.

Mobile devices are deﬁ ned as products that are not used closer than 20cm to the human body, whereas

portable devices can be used closer that 20cm to the body. In the case where the BTM411 module is used

in a portable device, additional SAR testing must be performed on the complete product.

If the FCC ID is not visible when the module is installed inside another device, then the outside of the device

into which the module is installed must also display a label referring to the enclosed module. This exterior label

can use wording such as the following: “Contains Transmitter Module FCC ID: PI4411B” or “Contains FCC ID:

PI4411B.” Any similar wording that expresses the same meaning may be used.

FCC and

Industry Canada

Statements

FCC Labelling

requirement