For the currently selected SSI channel (see ssi.channel) outputs a string of byte data to the slave device and simultaneously inputs the same amount of data from the slave device.
ssi.str(byref txdata as string, ack_bit as no_yes) as string
A string of the same length as txdata or less if the transmission ended prematurely due to the acknowledgement error.
Sending and Receiving Data,
The string to send to the slave device.
0- NO: transmit/receive byte data as 8-bit words, without the use of the acknowledgement bit.
1- YES: transmit/receive byte data as 9-bit words comprising 8 bits of data and the acknowledgement bit.
This method can be invoked only when ssi.enabled= 1- YES.