The fact that you are behind bars doesn't mean that you can't have visitation rights for your kid if you are separated from their parent. However, you will have to prove why you should have this right just as you would if you were free. Here are three factors that may determine your case:
Distance to Prison
You aren't likely to get visitation rights if you are incarcerated far from the child's current home. This may be the case, for example, if you are serving time in an out-of-state prison. It may be impractical (both in terms of money and school/work obligations) for the child and their guardian to travel across state lines to visit you regularly. The child's visits to jail should not create an undue hardship for them or the custodial parent. After all, they didn't do anything to contribute to your situation, so they shouldn't be punished for it.
Relationship with the Kid
Your relationship with the child will also come to question. Courts are generally reluctant to break strong bonds between parents and children. Therefore, absence other factors, the court may allow visitations if you already have a strong bond with the kid.
For example, you have a strong bond with your kid if you were living at home prior to your conviction, you used to take the kids to school, usually held birthday parties, and went on family vacations. However, your relationship with the child is probably weak if you were an absentee parent who lived out of state and rarely visited or communicated with the kid.
The Type of Crime
The nature of the crime of which you have been convicted also determines whether or not you are allowed contact with the child. You have higher chances of winning your visitation battle if you aren't seen as likely to corrupt the child or harm them in any way. This means violent crimes, abuse, drugs, or crimes against children will make it difficult for you to gain visitation rights. For example, you are likely to lose your visitation battle if you have been convicted of beating your wife and kids, but not if you were convicted of misappropriating your company's funds.
You have your work cut out for you because you need to prove that it is in your kid's best interest, and not your best interest, to get visitation rights. Why not make the work easier by consulting an experienced child custody lawyer?