4 Channel 4-20mA Transmitter

Hi, I am not getting any output for channel 1 on my 4 channel transmitter. I can detect the device I2C ID as 0x0c but the following Python code does not produce any output. The transmiiter is powered by a 12v supply and the psu in the output circuit is 24v. Please help as I am under a serious time constraint: PS - I’ve posted this on the Python thread as well - sorry for any duplication. Thanks in advance:

import smbus
import time

Get I2C bus

bus = smbus.SMBus(1)

while True:
for i in range(0,4095):
data1 = (i>>4)
data2 = (i&15)<<4
data = [data1, data2]
bus.write_i2c_block_data(0x60, 0x31, data)
#bus.write_byte_data(0x0c, 0x31,data1)
#bus.write_byte_data(0x0c, 0x31,data2)
print ("Writing on DAC %d DAC value " %i)
i = i+1