translate to AEC states. 
Byte Value AEC State Value (Byte Value - 132) AEC State Description
132 0 Idle
133 1 Transmit
134 2 Receive
135 3 Double Talk
Here's an example BLDATA message to clear things up. 
S01BLDATApèppçppppppèä
The first four bytes (pèpp) consist of only two values. 
p = 0x70 = 112 → 112 - 132 = -20 
è = 0x8A = 138 → 138 - 132 = 6 
So, the signal at input A is at 6 dB, while the signals at the rest of the inputs are at -20 dB. 
The next five bytes (çpppp) consist of only two values. 
p = 0x70 = 112 → 112 - 132 = -20 
ç = 0x87 = 135 → 135 - 132 = 3 
So, the signal at output 1 is at 3 dB, while the signals at the rest of the outputs are at -20 dB. 
The next byte (p) consists of only one value. 
p = 0x70 = 112 → 112 - 132 = -20 
So, the signal level of the AEC reference is -20 dB. 
The next byte (p) consists of only one value. 
p = 0x70 = 112 → 112 - 132 = -20 
So, we know that the room gain for input 1 is -20 dB. 
The next byte (è) consists of only one value. 
è = 0x8A = 138 → 138 - 132 = 6 
So, we know that the AGC gain for input1 1 is 6 dB.