How can I achieve the highest throughput from the RN 4x module? What throughput is possible?

We have performed some throughput testing, and have described the setup and results below. Test 3 is most relevant in many cases. This shows throughput between two RN42 devices. This will typically be the highest throughput attainable.

1

Tera Term Setup - v4.79

Baud = 115,200
Flow Ctrl = Hardware

2

After baud rate change

Baud = 921,600

3

Test

File transfer using File -> Transfer ZModem Send from one device, and File -> Transfer ZModem Receive from the other.
Send 400KB file, and watch transfer rate to determine throughput.

Test 1

$ // Test to see if in fast data mode once connection is made
f,1 // If command mode is entered, issue "f,1" to leave command mode and enter fast data mode

Device 1 - RN-42-EK (v6.15) - Master Device 2 - RN-USB-X (v4.73) - Slave
$
sf,1
r,1
$
sa,0
st, 0
su,921
r,1
$ // Baud = 921k
sr,0006660968B1
c
$
sf,1
r,1
$
st,0
su,921
r,1
$ // Baud = 921k
d // Display MAC address
r,1
Results
File -> Transfer ZModem
EK Send -> USB-X Receive = 21.4 KBps = 171 Kbps
USB-X send -> EK Receive = 17.4 KBps = 139 Kbps

Test 2

$ // Test to see if in fast data mode once connection is made
f,1 // If command mode is entered, issue "f,1" to leave command mode and enter fast data mode

Device 1 - RN-42-EK (v6.15) - Slave Device 2 - RN-USB-X (v4.73) - Master
$
sf,1
r,1
$
sa,0
st,0
su,921
r,1
$
// Baud = 921k
d // Display MAC address
r,1
$
sf,1
r,1
$
st,0
su,921
r,1
$
// Baud = 921K
sr, 0006664B2969
c
Results
File -> Transfer ZModem
USB-X send -> EK Receive = 23.5 KBps = 188 Kbps
EK Send -> USB-X Receive = 17.4 KBps = 139.2 Kbps

Test 3

$ // Test to see if in fast data mode once connection is made
f,1 // If command mode is entered, issue "f,1" to leave command mode and enter fast data mode

Device 1 - RN-42-EK (v6.15) - Master Device 2 - RN-42-EK (v6.15) - Slave
$
sf,1
r,1
$
sa,0
st,0
su,921
r,1
$ // Baud = 921k
sr, 0006664B39A9
c
$
sf,1
r,1
$
sa,0
st,0
su,921
r,1
$ // Baud = 921k
d // Display MAC address
r,1
Results
File -> Transfer ZModem
Master Send -> Slave Receive = 46.3 KBps = 370.4 Kbps
Slave Send -> Master Receive = 42.3 KBps = 338.4 Kbps

Test 4

$ // Test to see if in fast data mode once connection is made
f,1 // If command mode is entered, issue "f,1" to leave command mode and enter fast data mode

Device 1 - PC Device 2 - RN-USB-X (v4.73) - Slave
Tera Term @ 921k $
sf,1
r,1
$
st,0
su,921
r,1
Results
File -> Transfer ZModem
PC Send -> USB-X Receive = 19.5 KBps = 156 Kbps
USB-X send -> PC Receive = 20.5 KBps = 164 Kbps

Test 5

$ // Test to see if in fast data mode once connection is made
f,1 // If command mode is entered, issue "f,1" to leave command mode and enter fast data mode

Device 1 - PC Device 2 - RN-42-EK (v6.15) - Slave
Tera Term @ 921k $
sf,1
r,1
$
st,0
su,921
r,1
Results
File -> Transfer ZModem
PC Send -> RN-42-EK Receive = 24.3 KBps = 194 Kbps
RN-42-EK send -> PC Receive = 47.8 KBps = 382.4 Kbps
© 2016 Microchip Technology, Inc.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.