CIS-36 in error-correcting traffic mode is using a horizontal line- and vertical block-error-detection. Each block has ten data frames and a parity frame. Each data frame has five data characters and one parity character. In case an error is detected the receiving station starts ask for a frame repetition (NAK instead of ACK) from the last complete and correctly received frame.

CIS-36 is operating with Symbol rates of 10, 20 or 40 Bd which is equivalent to tone duration of 100, 50 or 25 ms.

Transmissions in CIS-36 are mostly in Russian using an ITA-2 alphabet. CIS-36 is a full-duplex mode with two transmission frequencies, but can also be used in simplex mode.

CIS-36 is based on the older PICCOLO-MK1 system. However, the signal is not symmetric and uses three frequency groups with 10, 11 and 11 frequencies. The tone spacing is 40 Hz. The theoretical bandwidth is 1400Hz.

In on-line crypto traffic mode the control tones #1, #12, # 24 and #36 are rarely sent so between the three frequency groups a spacing of 80 Hz seems to appear.

The decoder shows the shift cursors at the tone position #2 and #35 (resulting in a 1320 Hz shift).

The 10 Bd variant is used for manually transmitted operator messages and is mostly unencrypted. The automatic switching of the tone length is initialized by control sequences.

When message traffic has to be sent, the system switches to 20 or 40 Bd. This part is either coded or online encrypted in almost every transmission. Special control sequences are used for transmission control, call set up and clearance.

CIS-36 also has SELCAL and link establishment features.